Search Results: "spwhitton"

16 November 2022

Antoine Beaupr : Wayland: i3 to Sway migration

I started migrating my graphical workstations to Wayland, specifically migrating from i3 to Sway. This is mostly to address serious graphics bugs in the latest Framwork laptop, but also something I felt was inevitable. The current status is that I've been able to convert my i3 configuration to Sway, and adapt my systemd startup sequence to the new environment. Screen sharing only works with Pipewire, so I also did that migration, which basically requires an upgrade to Debian bookworm to get a nice enough Pipewire release. I'm testing Wayland on my laptop, but I'm not using it as a daily driver because I first need to upgrade to Debian bookworm on my main workstation. Most irritants have been solved one way or the other. My main problem with Wayland right now is that I spent a frigging week doing the conversion: it's exciting and new, but it basically sucked the life out of all my other projects and it's distracting, and I want it to stop. The rest of this page documents why I made the switch, how it happened, and what's left to do. Hopefully it will keep you from spending as much time as I did in fixing this. TL;DR: Wayland is mostly ready. Main blockers you might find are that you need to do manual configurations, DisplayLink (multiple monitors on a single cable) doesn't work in Sway, HDR and color management are still in development. I had to install the following packages:
apt install \
    brightnessctl \
    foot \
    gammastep \
    gdm3 \
    grim slurp \
    pipewire-pulse \
    sway \
    swayidle \
    swaylock \
    wdisplays \
    wev \
    wireplumber \
    wlr-randr \
    xdg-desktop-portal-wlr
And did some of tweaks in my $HOME, mostly dealing with my esoteric systemd startup sequence, which you won't have to deal with if you are not a fan.

Why switch? I originally held back from migrating to Wayland: it seemed like a complicated endeavor hardly worth the cost. It also didn't seem actually ready. But after reading this blurb on LWN, I decided to at least document the situation here. The actual quote that convinced me it might be worth it was:
It s amazing. I have never experienced gaming on Linux that looked this smooth in my life.
... I'm not a gamer, but I do care about latency. The longer version is worth a read as well. The point here is not to bash one side or the other, or even do a thorough comparison. I start with the premise that Xorg is likely going away in the future and that I will need to adapt some day. In fact, the last major Xorg release (21.1, October 2021) is rumored to be the last ("just like the previous release...", that said, minor releases are still coming out, e.g. 21.1.4). Indeed, it seems even core Xorg people have moved on to developing Wayland, or at least Xwayland, which was spun off it its own source tree. X, or at least Xorg, in in maintenance mode and has been for years. Granted, the X Window System is getting close to forty years old at this point: it got us amazingly far for something that was designed around the time the first graphical interface. Since Mac and (especially?) Windows released theirs, they have rebuilt their graphical backends numerous times, but UNIX derivatives have stuck on Xorg this entire time, which is a testament to the design and reliability of X. (Or our incapacity at developing meaningful architectural change across the entire ecosystem, take your pick I guess.) What pushed me over the edge is that I had some pretty bad driver crashes with Xorg while screen sharing under Firefox, in Debian bookworm (around November 2022). The symptom would be that the UI would completely crash, reverting to a text-only console, while Firefox would keep running, audio and everything still working. People could still see my screen, but I couldn't, of course, let alone interact with it. All processes still running, including Xorg. (And no, sorry, I haven't reported that bug, maybe I should have, and it's actually possible it comes up again in Wayland, of course. But at first, screen sharing didn't work of course, so it's coming a much further way. After making screen sharing work, though, the bug didn't occur again, so I consider this a Xorg-specific problem until further notice.) There were also frustrating glitches in the UI, in general. I actually had to setup a compositor alongside i3 to make things bearable at all. Video playback in a window was laggy, sluggish, and out of sync. Wayland fixed all of this.

Wayland equivalents This section documents each tool I have picked as an alternative to the current Xorg tool I am using for the task at hand. It also touches on other alternatives and how the tool was configured. Note that this list is based on the series of tools I use in desktop. TODO: update desktop with the following when done, possibly moving old configs to a ?xorg archive.

Window manager: i3 sway This seems like kind of a no-brainer. Sway is around, it's feature-complete, and it's in Debian. I'm a bit worried about the "Drew DeVault community", to be honest. There's a certain aggressiveness in the community I don't like so much; at least an open hostility towards more modern UNIX tools like containers and systemd that make it hard to do my work while interacting with that community. I'm also concern about the lack of unit tests and user manual for Sway. The i3 window manager has been designed by a fellow (ex-)Debian developer I have a lot of respect for (Michael Stapelberg), partly because of i3 itself, but also working with him on other projects. Beyond the characters, i3 has a user guide, a code of conduct, and lots more documentation. It has a test suite. Sway has... manual pages, with the homepage just telling users to use man -k sway to find what they need. I don't think we need that kind of elitism in our communities, to put this bluntly. But let's put that aside: Sway is still a no-brainer. It's the easiest thing to migrate to, because it's mostly compatible with i3. I had to immediately fix those resources to get a minimal session going:
i3 Sway note
set_from_resources set no support for X resources, naturally
new_window pixel 1 default_border pixel 1 actually supported in i3 as well
That's it. All of the other changes I had to do (and there were actually a lot) were all Wayland-specific changes, not Sway-specific changes. For example, use brightnessctl instead of xbacklight to change the backlight levels. See a copy of my full sway/config for details. Other options include:
  • dwl: tiling, minimalist, dwm for Wayland, not in Debian
  • Hyprland: tiling, fancy animations, not in Debian
  • Qtile: tiling, extensible, in Python, not in Debian (1015267)
  • river: Zig, stackable, tagging, not in Debian (1006593)
  • velox: inspired by xmonad and dwm, not in Debian
  • vivarium: inspired by xmonad, not in Debian

Status bar: py3status waybar I have invested quite a bit of effort in setting up my status bar with py3status. It supports Sway directly, and did not actually require any change when migrating to Wayland. Unfortunately, I had trouble making nm-applet work. Based on this nm-applet.service, I found that you need to pass --indicator for it to show up at all. In theory, tray icon support was merged in 1.5, but in practice there are still several limitations, like icons not clickable. Also, on startup, nm-applet --indicator triggers this error in the Sway logs:
nov 11 22:34:12 angela sway[298938]: 00:49:42.325 [INFO] [swaybar/tray/host.c:24] Registering Status Notifier Item ':1.47/org/ayatana/NotificationItem/nm_applet'
nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet IconPixmap: No such property  IconPixmap 
nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet AttentionIconPixmap: No such property  AttentionIconPixmap 
nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet ItemIsMenu: No such property  ItemIsMenu 
nov 11 22:36:10 angela sway[313419]: info: fcft.c:838: /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf: size=24.00pt/32px, dpi=96.00
... but that seems innocuous. The tray icon displays but is not clickable. Note that there is currently (November 2022) a pull request to hook up a "Tray D-Bus Menu" which, according to Reddit might fix this, or at least be somewhat relevant. If you don't see the icon, check the bar.tray_output property in the Sway config, try: tray_output *. The non-working tray was the biggest irritant in my migration. I have used nmtui to connect to new Wifi hotspots or change connection settings, but that doesn't support actions like "turn off WiFi". I eventually fixed this by switching from py3status to waybar, which was another yak horde shaving session, but ultimately, it worked.

Web browser: Firefox Firefox has had support for Wayland for a while now, with the team enabling it by default in nightlies around January 2022. It's actually not easy to figure out the state of the port, the meta bug report is still open and it's huge: it currently (Sept 2022) depends on 76 open bugs, it was opened twelve (2010) years ago, and it's still getting daily updates (mostly linking to other tickets). Firefox 106 presumably shipped with "Better screen sharing for Windows and Linux Wayland users", but I couldn't quite figure out what those were. TL;DR: echo MOZ_ENABLE_WAYLAND=1 >> ~/.config/environment.d/firefox.conf && apt install xdg-desktop-portal-wlr

How to enable it Firefox depends on this silly variable to start correctly under Wayland (otherwise it starts inside Xwayland and looks fuzzy and fails to screen share):
MOZ_ENABLE_WAYLAND=1 firefox
To make the change permanent, many recipes recommend adding this to an environment startup script:
if [ "$XDG_SESSION_TYPE" == "wayland" ]; then
    export MOZ_ENABLE_WAYLAND=1
fi
At least that's the theory. In practice, Sway doesn't actually run any startup shell script, so that can't possibly work. Furthermore, XDG_SESSION_TYPE is not actually set when starting Sway from gdm3 which I find really confusing, and I'm not the only one. So the above trick doesn't actually work, even if the environment (XDG_SESSION_TYPE) is set correctly, because we don't have conditionals in environment.d(5). (Note that systemd.environment-generator(7) do support running arbitrary commands to generate environment, but for some some do not support user-specific configuration files... Even then it may be a solution to have a conditional MOZ_ENABLE_WAYLAND environment, but I'm not sure it would work because ordering between those two isn't clear: maybe the XDG_SESSION_TYPE wouldn't be set just yet...) At first, I made this ridiculous script to workaround those issues. Really, it seems to me Firefox should just parse the XDG_SESSION_TYPE variable here... but then I realized that Firefox works fine in Xorg when the MOZ_ENABLE_WAYLAND is set. So now I just set that variable in environment.d and It Just Works :
MOZ_ENABLE_WAYLAND=1

Screen sharing Out of the box, screen sharing doesn't work until you install xdg-desktop-portal-wlr or similar (e.g. xdg-desktop-portal-gnome on GNOME). I had to reboot for the change to take effect. Without those tools, it shows the usual permission prompt with "Use operating system settings" as the only choice, but when we accept... nothing happens. After installing the portals, it actualyl works, and works well! This was tested in Debian bookworm/testing with Firefox ESR 102 and Firefox 106. Major caveat: we can only share a full screen, we can't currently share just a window. The major upside to that is that, by default, it streams only one output which is actually what I want most of the time! See the screencast compatibility for more information on what is supposed to work. This is actually a huge improvement over the situation in Xorg, where Firefox can only share a window or all monitors, which led me to use Chromium a lot for video-conferencing. With this change, in other words, I will not need Chromium for anything anymore, whoohoo! If slurp, wofi, or bemenu are installed, one of them will be used to pick the monitor to share, which effectively acts as some minimal security measure. See xdg-desktop-portal-wlr(1) for how to configure that.

Side note: Chrome fails to share a full screen I was still using Google Chrome (or, more accurately, Debian's Chromium package) for some videoconferencing. It's mainly because Chromium was the only browser which will allow me to share only one of my two monitors, which is extremely useful. To start chrome with the Wayland backend, you need to use:
chromium  -enable-features=UseOzonePlatform -ozone-platform=wayland
If it shows an ugly gray border, check the Use system title bar and borders setting. It can do some screensharing. Sharing a window and a tab seems to work, but sharing a full screen doesn't: it's all black. Maybe not ready for prime time. And since Firefox can do what I need under Wayland now, I will not need to fight with Chromium to work under Wayland:
apt purge chromium
Note that a similar fix was necessary for Signal Desktop, see this commit. Basically you need to figure out a way to pass those same flags to signal:
--enable-features=WaylandWindowDecorations --ozone-platform-hint=auto

Email: notmuch See Emacs, below.

File manager: thunar Unchanged.

News: feed2exec, gnus See Email, above, or Emacs in Editor, below.

Editor: Emacs okay-ish Emacs is being actively ported to Wayland. According to this LWN article, the first (partial, to Cairo) port was done in 2014 and a working port (to GTK3) was completed in 2021, but wasn't merged until late 2021. That is: after Emacs 28 was released (April 2022). So we'll probably need to wait for Emacs 29 to have native Wayland support in Emacs, which, in turn, is unlikely to arrive in time for the Debian bookworm freeze. There are, however, unofficial builds for both Emacs 28 and 29 provided by spwhitton which may provide native Wayland support. I tested the snapshot packages and they do not quite work well enough. First off, they completely take over the builtin Emacs they hijack the $PATH in /etc! and certain things are simply not working in my setup. For example, this hook never gets ran on startup:
(add-hook 'after-init-hook 'server-start t) 
Still, like many X11 applications, Emacs mostly works fine under Xwayland. The clipboard works as expected, for example. Scaling is a bit of an issue: fonts look fuzzy. I have heard anecdotal evidence of hard lockups with Emacs running under Xwayland as well, but haven't experienced any problem so far. I did experience a Wayland crash with the snapshot version however. TODO: look again at Wayland in Emacs 29.

Backups: borg Mostly irrelevant, as I do not use a GUI.

Color theme: srcery, redshift gammastep I am keeping Srcery as a color theme, in general. Redshift is another story: it has no support for Wayland out of the box, but it's apparently possible to apply a hack on the TTY before starting Wayland, with:
redshift -m drm -PO 3000
This tip is from the arch wiki which also has other suggestions for Wayland-based alternatives. Both KDE and GNOME have their own "red shifters", and for wlroots-based compositors, they (currently, Sept. 2022) list the following alternatives: I configured gammastep with a simple gammastep.service file associated with the sway-session.target.

Display manager: lightdm gdm3 Switched because lightdm failed to start sway:
nov 16 16:41:43 angela sway[843121]: 00:00:00.002 [ERROR] [wlr] [libseat] [common/terminal.c:162] Could not open target tty: Permission denied
Possible alternatives:

Terminal: xterm foot One of the biggest question mark in this transition was what to do about Xterm. After writing two articles about terminal emulators as a professional journalist, decades of working on the terminal, and probably using dozens of different terminal emulators, I'm still not happy with any of them. This is such a big topic that I actually have an entire blog post specifically about this. For starters, using xterm under Xwayland works well enough, although the font scaling makes things look a bit too fuzzy. I have also tried foot: it ... just works! Fonts are much crisper than Xterm and Emacs. URLs are not clickable but the URL selector (control-shift-u) is just plain awesome (think "vimperator" for the terminal). There's cool hack to jump between prompts. Copy-paste works. True colors work. The word-wrapping is excellent: it doesn't lose one byte. Emojis are nicely sized and colored. Font resize works. There's even scroll back search (control-shift-r). Foot went from a question mark to being a reason to switch to Wayland, just for this little goodie, which says a lot about the quality of that software. The selection clicks are a not quite what I would expect though. In rxvt and others, you have the following patterns:
  • single click: reset selection, or drag to select
  • double: select word
  • triple: select quotes or line
  • quadruple: select line
I particularly find the "select quotes" bit useful. It seems like foot just supports double and triple clicks, with word and line selected. You can select a rectangle with control,. It correctly extends the selection word-wise with right click if double-click was first used. One major problem with Foot is that it's a new terminal, with its own termcap entry. Support for foot was added to ncurses in the 20210731 release, which was shipped after the current Debian stable release (Debian bullseye, which ships 6.2+20201114-2). A workaround for this problem is to install the foot-terminfo package on the remote host, which is available in Debian stable. This should eventually resolve itself, as Debian bookworm has a newer version. Note that some corrections were also shipped in the 20211113 release, but that is also shipped in Debian bookworm. That said, I am almost certain I will have to revert back to xterm under Xwayland at some point in the future. Back when I was using GNOME Terminal, it would mostly work for everything until I had to use the serial console on a (HP ProCurve) network switch, which have a fancy TUI that was basically unusable there. I fully expect such problems with foot, or any other terminal than xterm, for that matter. The foot wiki has good troubleshooting instructions as well. Update: I did find one tiny thing to improve with foot, and it's the default logging level which I found pretty verbose. After discussing it with the maintainer on IRC, I submitted this patch to tweak it, which I described like this on Mastodon:
today's reason why i will go to hell when i die (TRWIWGTHWID?): a 600-word, 63 lines commit log for a one line change: https://codeberg.org/dnkl/foot/pulls/1215
It's Friday.

Launcher: rofi rofi?? rofi does not support Wayland. There was a rather disgraceful battle in the pull request that led to the creation of a fork (lbonn/rofi), so it's unclear how that will turn out. Given how relatively trivial problem space is, there is of course a profusion of options:
Tool In Debian Notes
alfred yes general launcher/assistant tool
bemenu yes, bookworm+ inspired by dmenu
cerebro no Javascript ... uh... thing
dmenu-wl no fork of dmenu, straight port to Wayland
Fuzzel ITP 982140 dmenu/drun replacement, app icon overlay
gmenu no drun replacement, with app icons
kickoff no dmenu/run replacement, fuzzy search, "snappy", history, copy-paste, Rust
krunner yes KDE's runner
mauncher no dmenu/drun replacement, math
nwg-launchers no dmenu/drun replacement, JSON config, app icons, nwg-shell project
Onagre no rofi/alfred inspired, multiple plugins, Rust
menu no dmenu/drun rewrite
Rofi (lbonn's fork) no see above
sirula no .desktop based app launcher
Ulauncher ITP 949358 generic launcher like Onagre/rofi/alfred, might be overkill
tofi yes, bookworm+ dmenu/drun replacement, C
wmenu no fork of dmenu-wl, but mostly a rewrite
Wofi yes dmenu/drun replacement, not actively maintained
yofi no dmenu/drun replacement, Rust
The above list comes partly from https://arewewaylandyet.com/ and awesome-wayland. It is likely incomplete. I have read some good things about bemenu, fuzzel, and wofi. A particularly tricky option is that my rofi password management depends on xdotool for some operations. At first, I thought this was just going to be (thankfully?) impossible, because we actually like the idea that one app cannot send keystrokes to another. But it seems there are actually alternatives to this, like wtype or ydotool, the latter which requires root access. wl-ime-type does that through the input-method-unstable-v2 protocol (sample emoji picker, but is not packaged in Debian. As it turns out, wtype just works as expected, and fixing this was basically a two-line patch. Another alternative, not in Debian, is wofi-pass. The other problem is that I actually heavily modified rofi. I use "modis" which are not actually implemented in wofi or tofi, so I'm left with reinventing those wheels from scratch or using the rofi + wayland fork... It's really too bad that fork isn't being reintegrated... For now, I'm actually still using rofi under Xwayland. The main downside is that fonts are fuzzy, but it otherwise just works. Note that wlogout could be a partial replacement (just for the "power menu").

Image viewers: geeqie ? I'm not very happy with geeqie in the first place, and I suspect the Wayland switch will just make add impossible things on top of the things I already find irritating (Geeqie doesn't support copy-pasting images). In practice, Geeqie doesn't seem to work so well under Wayland. The fonts are fuzzy and the thumbnail preview just doesn't work anymore (filed as Debian bug 1024092). It seems it also has problems with scaling. Alternatives: See also this list and that list for other list of image viewers, not necessarily ported to Wayland. TODO: pick an alternative to geeqie, nomacs would be gorgeous if it wouldn't be basically abandoned upstream (no release since 2020), has an unpatched CVE-2020-23884 since July 2020, does bad vendoring, and is in bad shape in Debian (4 minor releases behind). So for now I'm still grumpily using Geeqie.

Media player: mpv, gmpc / sublime This is basically unchanged. mpv seems to work fine under Wayland, better than Xorg on my new laptop (as mentioned in the introduction), and that before the version which improves Wayland support significantly, by bringing native Pipewire support and DMA-BUF support. gmpc is more of a problem, mainly because it is abandoned. See 2022-08-22-gmpc-alternatives for the full discussion, one of the alternatives there will likely support Wayland. Finally, I might just switch to sublime-music instead... In any case, not many changes here, thankfully.

Screensaver: xsecurelock swaylock I was previously using xss-lock and xsecurelock as a screensaver, with xscreensaver "hacks" as a backend for xsecurelock. The basic screensaver in Sway seems to be built with swayidle and swaylock. It's interesting because it's the same "split" design as xss-lock and xsecurelock. That, unfortunately, does not include the fancy "hacks" provided by xscreensaver, and that is unlikely to be implemented upstream. Other alternatives include gtklock and waylock (zig), which do not solve that problem either. It looks like swaylock-plugin, a swaylock fork, which at least attempts to solve this problem, although not directly using the real xscreensaver hacks. swaylock-effects is another attempt at this, but it only adds more effects, it doesn't delegate the image display. Other than that, maybe it's time to just let go of those funky animations and just let swaylock do it's thing, which is display a static image or just a black screen, which is fine by me. In the end, I am just using swayidle with a configuration based on the systemd integration wiki page but with additional tweaks from this service, see the resulting swayidle.service file. Interestingly, damjan also has a service for swaylock itself, although it's not clear to me what its purpose is...

Screenshot: maim grim, pubpaste I'm a heavy user of maim (and a package uploader in Debian). It looks like the direct replacement to maim (and slop) is grim (and slurp). There's also swappy which goes on top of grim and allows preview/edit of the resulting image, nice touch (not in Debian though). See also awesome-wayland screenshots for other alternatives: there are many, including X11 tools like Flameshot that also support Wayland. One key problem here was that I have my own screenshot / pastebin software which will needed an update for Wayland as well. That, thankfully, meant actually cleaning up a lot of horrible code that involved calling xterm and xmessage for user interaction. Now, pubpaste uses GTK for prompts and looks much better. (And before anyone freaks out, I already had to use GTK for proper clipboard support, so this isn't much of a stretch...)

Screen recorder: simplescreenrecorder wf-recorder In Xorg, I have used both peek or simplescreenrecorder for screen recordings. The former will work in Wayland, but has no sound support. The latter has a fork with Wayland support but it is limited and buggy ("doesn't support recording area selection and has issues with multiple screens"). It looks like wf-recorder will just do everything correctly out of the box, including audio support (with --audio, duh). It's also packaged in Debian. One has to wonder how this works while keeping the "between app security" that Wayland promises, however... Would installing such a program make my system less secure? Many other options are available, see the awesome Wayland screencasting list.

RSI: workrave nothing? Workrave has no support for Wayland. activity watch is a time tracker alternative, but is not a RSI watcher. KDE has rsiwatcher, but that's a bit too much on the heavy side for my taste. SafeEyes looks like an alternative at first, but it has many issues under Wayland (escape doesn't work, idle doesn't work, it just doesn't work really). timekpr-next could be an alternative as well, and has support for Wayland. I am also considering just abandoning workrave, even if I stick with Xorg, because it apparently introduces significant latency in the input pipeline. And besides, I've developed a pretty unhealthy alert fatigue with Workrave. I have used the program for so long that my fingers know exactly where to click to dismiss those warnings very effectively. It makes my work just more irritating, and doesn't fix the fundamental problem I have with computers.

Other apps This is a constantly changing list, of course. There's a bit of a "death by a thousand cuts" in migrating to Wayland because you realize how many things you were using are tightly bound to X.
  • .Xresources - just say goodbye to that old resource system, it was used, in my case, only for rofi, xterm, and ... Xboard!?
  • keyboard layout switcher: built-in to Sway since 2017 (PR 1505, 1.5rc2+), requires a small configuration change, see this answer as well, looks something like this command:
     swaymsg input 0:0:X11_keyboard xkb_layout de
    
    or using this config:
     input *  
         xkb_layout "ca,us"
         xkb_options "grp:sclk_toggle"
      
    
    That works refreshingly well, even better than in Xorg, I must say. swaykbdd is an alternative that supports per-window layouts (in Debian).
  • wallpaper: currently using feh, will need a replacement, TODO: figure out something that does, like feh, a random shuffle. swaybg just loads a single image, duh. oguri might be a solution, but unmaintained, used here, not in Debian. wallutils is another option, also not in Debian. For now I just don't have a wallpaper, the background is a solid gray, which is better than Xorg's default (which is whatever crap was left around a buffer by the previous collection of programs, basically)
  • notifications: currently using dunst in some places, which works well in both Xorg and Wayland, not a blocker, salut a possible alternative (not in Debian), damjan uses mako. TODO: install dunst everywhere
  • notification area: I had trouble making nm-applet work. based on this nm-applet.service, I found that you need to pass --indicator. In theory, tray icon support was merged in 1.5, but in practice there are still several limitations, like icons not clickable. On startup, nm-applet --indicator triggers this error in the Sway logs:
     nov 11 22:34:12 angela sway[298938]: 00:49:42.325 [INFO] [swaybar/tray/host.c:24] Registering Status Notifier Item ':1.47/org/ayatana/NotificationItem/nm_applet'
     nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet IconPixmap: No such property  IconPixmap 
     nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet AttentionIconPixmap: No such property  AttentionIconPixmap 
     nov 11 22:34:12 angela sway[298938]: 00:49:42.327 [ERROR] [swaybar/tray/item.c:127] :1.47/org/ayatana/NotificationItem/nm_applet ItemIsMenu: No such property  ItemIsMenu 
     nov 11 22:36:10 angela sway[313419]: info: fcft.c:838: /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf: size=24.00pt/32px, dpi=96.00
    
    ... but it seems innocuous. The tray icon displays but, as stated above, is not clickable. If you don't see the icon, check the bar.tray_output property in the Sway config, try: tray_output *. Note that there is currently (November 2022) a pull request to hook up a "Tray D-Bus Menu" which, according to Reddit might fix this, or at least be somewhat relevant. This was the biggest irritant in my migration. I have used nmtui to connect to new Wifi hotspots or change connection settings, but that doesn't support actions like "turn off WiFi". I eventually fixed this by switching from py3status to waybar.
  • window switcher: in i3 I was using this bespoke i3-focus script, which doesn't work under Sway, swayr an option, not in Debian. So I put together this other bespoke hack from multiple sources, which works.
  • PDF viewer: currently using atril (which supports Wayland), could also just switch to zatura/mupdf permanently, see also calibre for a discussion on document viewers
See also this list of useful addons and this other list for other app alternatives.

More X11 / Wayland equivalents For all the tools above, it's not exactly clear what options exist in Wayland, or when they do, which one should be used. But for some basic tools, it seems the options are actually quite clear. If that's the case, they should be listed here:
X11 Wayland In Debian
arandr wdisplays yes
autorandr kanshi yes
xdotool wtype yes
xev wev yes
xlsclients swaymsg -t get_tree yes
xrandr wlr-randr yes
lswt is a more direct replacement for xlsclients but is not packaged in Debian. See also: Note that arandr and autorandr are not directly part of X. arewewaylandyet.com refers to a few alternatives. We suggest wdisplays and kanshi above (see also this service file) but wallutils can also do the autorandr stuff, apparently, and nwg-displays can do the arandr part. Neither are packaged in Debian yet. So I have tried wdisplays and it Just Works, and well. The UI even looks better and more usable than arandr, so another clean win from Wayland here. TODO: test kanshi as a autorandr replacement

Other issues

systemd integration I've had trouble getting session startup to work. This is partly because I had a kind of funky system to start my session in the first place. I used to have my whole session started from .xsession like this:
#!/bin/sh
. ~/.shenv
systemctl --user import-environment
exec systemctl --user start --wait xsession.target
But obviously, the xsession.target is not started by the Sway session. It seems to just start a default.target, which is really not what we want because we want to associate the services directly with the graphical-session.target, so that they don't start when logging in over (say) SSH. damjan on #debian-systemd showed me his sway-setup which features systemd integration. It involves starting a different session in a completely new .desktop file. That work was submitted upstream but refused on the grounds that "I'd rather not give a preference to any particular init system." Another PR was abandoned because "restarting sway does not makes sense: that kills everything". The work was therefore moved to the wiki. So. Not a great situation. The upstream wiki systemd integration suggests starting the systemd target from within Sway, which has all sorts of problems:
  • you don't get Sway logs anywhere
  • control groups are all messed up
I have done a lot of work trying to figure this out, but I remember that starting systemd from Sway didn't actually work for me: my previously configured systemd units didn't correctly start, and especially not with the right $PATH and environment. So I went down that rabbit hole and managed to correctly configure Sway to be started from the systemd --user session. I have partly followed the wiki but also picked ideas from damjan's sway-setup and xdbob's sway-services. Another option is uwsm (not in Debian). This is the config I have in .config/systemd/user/: I have also configured those services, but that's somewhat optional: You will also need at least part of my sway/config, which sends the systemd notification (because, no, Sway doesn't support any sort of readiness notification, that would be too easy). And you might like to see my swayidle-config while you're there. Finally, you need to hook this up somehow to the login manager. This is typically done with a desktop file, so drop sway-session.desktop in /usr/share/wayland-sessions and sway-user-service somewhere in your $PATH (typically /usr/bin/sway-user-service). The session then looks something like this:
$ systemd-cgls   head -101
Control group /:
-.slice
 user.slice (#472)
    user.invocation_id: bc405c6341de4e93a545bde6d7abbeec
    trusted.invocation_id: bc405c6341de4e93a545bde6d7abbeec
   user-1000.slice (#10072)
      user.invocation_id: 08f40f5c4bcd4fd6adfd27bec24e4827
      trusted.invocation_id: 08f40f5c4bcd4fd6adfd27bec24e4827
     user@1000.service   (#10156)
        user.delegate: 1
        trusted.delegate: 1
        user.invocation_id: 76bed72a1ffb41dca9bfda7bb174ef6b
        trusted.invocation_id: 76bed72a1ffb41dca9bfda7bb174ef6b
       session.slice (#10282)
         xdg-document-portal.service (#12248)
           9533 /usr/libexec/xdg-document-portal
           9542 fusermount3 -o rw,nosuid,nodev,fsname=portal,auto_unmount,subt 
         xdg-desktop-portal.service (#12211)
           9529 /usr/libexec/xdg-desktop-portal
         pipewire-pulse.service (#10778)
           6002 /usr/bin/pipewire-pulse
         wireplumber.service (#10519)
           5944 /usr/bin/wireplumber
         gvfs-daemon.service (#10667)
           5960 /usr/libexec/gvfsd
         gvfs-udisks2-volume-monitor.service (#10852)
           6021 /usr/libexec/gvfs-udisks2-volume-monitor
         at-spi-dbus-bus.service (#11481)
           6210 /usr/libexec/at-spi-bus-launcher
           6216 /usr/bin/dbus-daemon --config-file=/usr/share/defaults/at-spi2 
           6450 /usr/libexec/at-spi2-registryd --use-gnome-session
         pipewire.service (#10403)
           5940 /usr/bin/pipewire
         dbus.service (#10593)
           5946 /usr/bin/dbus-daemon --session --address=systemd: --nofork --n 
       background.slice (#10324)
         tracker-miner-fs-3.service (#10741)
           6001 /usr/libexec/tracker-miner-fs-3
       app.slice (#10240)
         xdg-permission-store.service (#12285)
           9536 /usr/libexec/xdg-permission-store
         gammastep.service (#11370)
           6197 gammastep
         dunst.service (#11958)
           7460 /usr/bin/dunst
         wterminal.service (#13980)
           69100 foot --title pop-up
           69101 /bin/bash
           77660 sudo systemd-cgls
           77661 head -101
           77662 wl-copy
           77663 sudo systemd-cgls
           77664 systemd-cgls
         syncthing.service (#11995)
           7529 /usr/bin/syncthing -no-browser -no-restart -logflags=0 --verbo 
           7537 /usr/bin/syncthing -no-browser -no-restart -logflags=0 --verbo 
         dconf.service (#10704)
           5967 /usr/libexec/dconf-service
         gnome-keyring-daemon.service (#10630)
           5951 /usr/bin/gnome-keyring-daemon --foreground --components=pkcs11 
         gcr-ssh-agent.service (#10963)
           6035 /usr/libexec/gcr-ssh-agent /run/user/1000/gcr
         swayidle.service (#11444)
           6199 /usr/bin/swayidle -w
         nm-applet.service (#11407)
           6198 /usr/bin/nm-applet --indicator
         wcolortaillog.service (#11518)
           6226 foot colortaillog
           6228 /bin/sh /home/anarcat/bin/colortaillog
           6230 sudo journalctl -f
           6233 ccze -m ansi
           6235 sudo journalctl -f
           6236 journalctl -f
         afuse.service (#10889)
           6051 /usr/bin/afuse -o mount_template=sshfs -o transform_symlinks - 
         gpg-agent.service (#13547)
           51662 /usr/bin/gpg-agent --supervised
           51719 scdaemon --multi-server
         emacs.service (#10926)
            6034 /usr/bin/emacs --fg-daemon
           33203 /usr/bin/aspell -a -m -d en --encoding=utf-8
         xdg-desktop-portal-gtk.service (#12322)
           9546 /usr/libexec/xdg-desktop-portal-gtk
         xdg-desktop-portal-wlr.service (#12359)
           9555 /usr/libexec/xdg-desktop-portal-wlr
         sway.service (#11037)
           6037 /usr/bin/sway
           6181 swaybar -b bar-0
           6209 py3status
           6309 /usr/bin/i3status -c /tmp/py3status_oy4ntfnq
           6969 Xwayland :0 -rootless -terminate -core -listen 29 -listen 30 - 
       init.scope (#10198)
         5909 /lib/systemd/systemd --user
         5911 (sd-pam)
     session-7.scope (#10440)
       5895 gdm-session-worker [pam/gdm-password]
       6028 /usr/libexec/gdm-wayland-session --register-session sway-user-serv 
[...]
I think that's pretty neat.

Environment propagation At first, my terminals and rofi didn't have the right $PATH, which broke a lot of my workflow. It's hard to tell exactly how Wayland gets started or where to inject environment. This discussion suggests a few alternatives and this Debian bug report discusses this issue as well. I eventually picked environment.d(5) since I already manage my user session with systemd, and it fixes a bunch of other problems. I used to have a .shenv that I had to manually source everywhere. The only problem with that approach is that it doesn't support conditionals, but that's something that's rarely needed.

Pipewire This is a whole topic onto itself, but migrating to Wayland also involves using Pipewire if you want screen sharing to work. You can actually keep using Pulseaudio for audio, that said, but that migration is actually something I've wanted to do anyways: Pipewire's design seems much better than Pulseaudio, as it folds in JACK features which allows for pretty neat tricks. (Which I should probably show in a separate post, because this one is getting rather long.) I first tried this migration in Debian bullseye, and it didn't work very well. Ardour would fail to export tracks and I would get into weird situations where streams would just drop mid-way. A particularly funny incident is when I was in a meeting and I couldn't hear my colleagues speak anymore (but they could) and I went on blabbering on my own for a solid 5 minutes until I realized what was going on. By then, people had tried numerous ways of letting me know that something was off, including (apparently) coughing, saying "hello?", chat messages, IRC, and so on, until they just gave up and left. I suspect that was also a Pipewire bug, but it could also have been that I muted the tab by error, as I recently learned that clicking on the little tiny speaker icon on a tab mutes that tab. Since the tab itself can get pretty small when you have lots of them, it's actually quite frequently that I mistakenly mute tabs. Anyways. Point is: I already knew how to make the migration, and I had already documented how to make the change in Puppet. It's basically:
apt install pipewire pipewire-audio-client-libraries pipewire-pulse wireplumber 
Then, as a regular user:
systemctl --user daemon-reload
systemctl --user --now disable pulseaudio.service pulseaudio.socket
systemctl --user --now enable pipewire pipewire-pulse
systemctl --user mask pulseaudio
An optional (but key, IMHO) configuration you should also make is to "switch on connect", which will make your Bluetooth or USB headset automatically be the default route for audio, when connected. In ~/.config/pipewire/pipewire-pulse.conf.d/autoconnect.conf:
context.exec = [
      path = "pactl"        args = "load-module module-always-sink"  
      path = "pactl"        args = "load-module module-switch-on-connect"  
    #  path = "/usr/bin/sh"  args = "~/.config/pipewire/default.pw"  
]
See the excellent as usual Arch wiki page about Pipewire for that trick and more information about Pipewire. Note that you must not put the file in ~/.config/pipewire/pipewire.conf (or pipewire-pulse.conf, maybe) directly, as that will break your setup. If you want to add to that file, first copy the template from /usr/share/pipewire/pipewire-pulse.conf first. So far I'm happy with Pipewire in bookworm, but I've heard mixed reports from it. I have high hopes it will become the standard media server for Linux in the coming months or years, which is great because I've been (rather boldly, I admit) on the record saying I don't like PulseAudio. Rereading this now, I feel it might have been a little unfair, as "over-engineered and tries to do too many things at once" applies probably even more to Pipewire than PulseAudio (since it also handles video dispatching). That said, I think Pipewire took the right approach by implementing existing interfaces like Pulseaudio and JACK. That way we're not adding a third (or fourth?) way of doing audio in Linux; we're just making the server better.

Keypress drops Sometimes I lose keyboard presses. This correlates with the following warning from Sway:
d c 06 10:36:31 curie sway[343384]: 23:32:14.034 [ERROR] [wlr] [libinput] event5  - SONiX USB Keyboard: client bug: event processing lagging behind by 37ms, your system is too slow 
... and corresponds to an open bug report in Sway. It seems the "system is too slow" should really be "your compositor is too slow" which seems to be the case here on this older system (curie). It doesn't happen often, but it does happen, particularly when a bunch of busy processes start in parallel (in my case: a linter running inside a container and notmuch new). The proposed fix for this in Sway is to gain real time privileges and add the CAP_SYS_NICE capability to the binary. We'll see how that goes in Debian once 1.8 gets released and shipped.

Improvements over i3

Tiling improvements There's a lot of improvements Sway could bring over using plain i3. There are pretty neat auto-tilers that could replicate the configurations I used to have in Xmonad or Awesome, see:

Display latency tweaks TODO: You can tweak the display latency in wlroots compositors with the max_render_time parameter, possibly getting lower latency than X11 in the end.

Sound/brightness changes notifications TODO: Avizo can display a pop-up to give feedback on volume and brightness changes. Not in Debian. Other alternatives include SwayOSD and sway-nc, also not in Debian.

Debugging tricks The xeyes (in the x11-apps package) will run in Wayland, and can actually be used to easily see if a given window is also in Wayland. If the "eyes" follow the cursor, the app is actually running in xwayland, so not natively in Wayland. Another way to see what is using Wayland in Sway is with the command:
swaymsg -t get_tree

Other documentation

Conclusion In general, this took me a long time, but it mostly works. The tray icon situation is pretty frustrating, but there's a workaround and I have high hopes it will eventually fix itself. I'm also actually worried about the DisplayLink support because I eventually want to be using this, but hopefully that's another thing that will hopefully fix itself before I need it.

A word on the security model I'm kind of worried about all the hacks that have been added to Wayland just to make things work. Pretty much everywhere we need to, we punched a hole in the security model: Wikipedia describes the security properties of Wayland as it "isolates the input and output of every window, achieving confidentiality, integrity and availability for both." I'm not sure those are actually realized in the actual implementation, because of all those holes punched in the design, at least in Sway. For example, apparently the GNOME compositor doesn't have the virtual-keyboard protocol, but they do have (another?!) text input protocol. Wayland does offer a better basis to implement such a system, however. It feels like the Linux applications security model lacks critical decision points in the UI, like the user approving "yes, this application can share my screen now". Applications themselves might have some of those prompts, but it's not mandatory, and that is worrisome.

24 October 2021

Sean Whitton: Deploying containers with Consfigurator

For some months now I ve been working on some patches to Consfigurator to add support for Linux containers. My goal is to make Consfigurator capable of both performing the initial setup of a container and of entering the running container to apply configuration. For the case of unprivileged LXCs running as non-root, my work-in-progress branch can now do both of these things. As Consfigurator enters the container directly using system calls, it should be decently fast at configuring multiple containers on a host, and it will also be possible to have it do this in parallel. The initial setup for the container uses Consfigurator s existing support for building root filesystems, and it should be easy to extend that to support arbitrary GNU/Linux distributions by teaching Consfigurator how to invoke bootstrapping tools other than debootstrap(8). Here s an example:
(defhost lxc1.silentflame.com ()
  (os:debian-stable "bullseye" :amd64)
  (basic-props)
  (apt:installed "systemd" "netcat")
  (apache:https-vhost ...))
(defhost lxctest.laptop.silentflame.com ()
  (os:debian-stable "bullseye" :amd64)
  (apt:proxy "http://192.168.122.1:3142")
  (basic-props)
  (apt:installed "linux-image-amd64" "lxc")
  (lxc:usernet-usable-by "spwhitton" "lxcbr0")
  (lxc:user-containers-autostart "spwhitton")
  (lxc:user-container-for '(:additional-lines
                            ("lxc.net.0.type = veth"
                             "lxc.net.0.flags = up"
                             "lxc.net.0.link = lxcbr0"
                             ...))
                          "spwhitton"
                          lxc1.silentflame.com))
(defhost laptop.silentflame.com ()
  ...
  (libvirt:kvm-boots-chroot-for '(:always-deploys t)
                                lxctest.laptop.silentflame.com))
This code is a simplified definition of my testing setup for this work. It defines three hosts: a container lxc1, a container host lxctest, and my laptop. When Consfigurator is asked to deploy the laptop, it will set up the root filesystem for lxctest and then boot it as a KVM virtual machine. Preparing that root filesystem will include setting up the root filesystem for lxc1, too, including shifting the ownership and ACLs to match the user namespace LXC will use when booting the container. Thus, once the deployment of the laptop is finished, it will be possible to boot the lxctest VM, connect to it as the user spwhitton, and start lxc1. Consfigurator includes only minimal support for setting up container networking, as there are so many different ways in which you might want to do it. In my own consfig I ve been developing properties to connect containers directly to my tinc VPN. A single tinc daemon runs on the container host, and other tinc daemons route a whole subnet, containing the addresses for each of the containers, to the container host s tinc daemon. As the LXCs Consfigurator sets up run as non-root, some sort of setuid facility is required to configure this networking. Consfigurator s ability to dump executable Lisp images is helping here. I define a function which runs as root to set up the networking:
(defun route-athenet-container-veth (host)
  (let ((user (getenv "USERV_USER"))
        (peer (getenv "USERV_U_PEER"))
        (ip (car (uiop:command-line-arguments))))
    (unless (string-prefix-p (format nil "veth~D_" (getenv "USERV_UID")) peer)
      (error "~A does not belong to requester." peer))
    (unless (member (cons user ip) (get-hostattrs 'veth-ips host) :test #'equal)
      (error "~A does not have permission to route ~A." user ip))
    (flet ((r (&rest args)
             ;; Explicitly passing nil means UIOP will not invoke a shell.
             (run-program args :force-shell nil)))
      (eswitch ((getenv "USERV_U_HOOK_TYPE") :test #'string=)
        ("up"
         (apply #'r
                "sysctl" "-w"
                "net.ipv6.conf.all.forwarding=1"
                ...)
         (r "ip" "addr" "flush" "dev" peer "scope" "link")
         (r "ip" "-6" "addr" "add" "fe80::1/64" "dev" peer)
         (r "ip" "-6" "route" "add" (strcat ip "/128") "dev" peer)
         ...)
        ("down"
         ...
         (r "ip" "-6" "route" "del" (strcat ip "/128") "dev" peer))))))
and then apply the following property to lxctest to dump an image which will call this function and then exit:
(image-dumped
 "/usr/lib/userv/route-athenet-container-veth"
  (route-athenet-container-veth ,(intern (string-upcase (get-hostname)))))
I m using GNU userv to enable ordinary users to run this image as root, so there there s a small script which converts LXC s LXC_HOOK_* environment variables into appropriate command line arguments to userv(1) such that the function above is able to access that information from its environment (the USERV_U_* variables above). You could just as easily do this with sudo, by giving permission for the relevant LXC_HOOK_* environment variables to survive the switch to root. What s particularly nice about this is that there s no need to write any code to keep a config file updated, specifying which users are allowed to route which IPs to their containers. ROUTE-ATHENET-CONTAINER-VETH receives a HOST value for the container host and can just look at the metadata established by properties for particular containers. Each time this metadata is updated and lxctest is deployed, a fresh image is dumped containing the updated metadata. This work has provided opportunities to make various other improvements to Consfigurator, especially with regard to dumping and reinvoking images. Making SBCL capable of entering user namespaces required a change upstream, which made it into the recent SBCL 2.1.8 release. I m very grateful to the SBCL developers for their engagement with my project. I ve been able to add a workaround so that Consfigurator can still enter user namespaces when run on the version of SBCL included in Debian stable. I also discovered that deploying all of my laptop, lxctest and lxc1 at once generates enough output to fill up a pipe, thus revealing a deadlock in Consfigurator s IPC, which it was good to become aware of and fix. That involved writing my first multi-threaded Lisp, as there are two pipes that need to be kept from filling up, and to my surprise it worked first time. Take that Haskell :)

15 September 2021

Ian Jackson: Get source to Debian packages only via dgit; "official" git links are beartraps

tl;dr dgit clone sourcepackage gets you the source code, as a git tree, in ./sourcepackage. cd into it and dpkg-buildpackage -uc -b. Do not use: "VCS" links on official Debian web pages like tracker.debian.org; "debcheckout"; searching Debian's gitlab (salsa.debian.org). These are good for Debian experts only. If you use Debian's "official" source git repo links you can easily build a package without Debian's patches applied.[1] This can even mean missing security patches. Or maybe it can't even be built in a normal way (or at all). OMG WTF BBQ, why? It's complicated. There is History. Debian's "most-official" centralised source repository is still the Debian Archive, which is a system based on tarballs and patches. I invented the Debian source package format in 1992/3 and it has been souped up since, but it's still tarballs and patches. This system is, of course, obsolete, now that we have modern version control systems, especially git. Maintainers of Debian packages have invented ways of using git anyway, of course. But this is not standardised. There is a bewildering array of approaches. The most common approach is to maintain git tree containing a pile of *.patch files, which are then often maintained using quilt. Yes, really, many Debian people are still using quilt, despite having git! There is machinery for converting this git tree containing a series of patches, to an "official" source package. If you don't use that machinery, and just build from git, nothing applies the patches. [1] This post was prompted by a conversation with a friend who had wanted to build a Debian package, and didn't know to use dgit. They had got the source from salsa via a link on tracker.d.o, and built .debs without Debian's patches. This not a theoretical unsoundness, but a very real practical risk. Future is not very bright In 2013 at the Debconf in Vaumarcus, Joey Hess, myself, and others, came up with a plan to try to improve this which we thought would be deployable. (Previous attempts had failed.) Crucially, this transition plan does not force change onto any of Debian's many packaging teams, nor onto people doing cross-package maintenance work. I worked on this for quite a while, and at a technical level it is a resounding success. Unfortunately there is a big limitation. At the current stage of the transition, to work at its best, this replacement scheme hopes that maintainers who update a package will use a new upload tool. The new tool fits into their existing Debian git packaging workflow and has some benefits, but it does make things more complicated rather than less (like any transition plan must, during the transitional phase). When maintainers don't use this new tool, the standardised git branch seen by users is a compatibility stub generated from the tarballs-and-patches. So it has the right contents, but useless history. The next step is to allow a maintainer to update a package without dealing with tarballs-and-patches at all. This would be massively more convenient for the maintainer, so an easy sell. And of course it links the tarballs-and-patches to the git history in a proper machine-readable way. We held a "git packaging requirements-gathering session" at the Curitiba Debconf in 2019. I think the DPL's intent was to try to get input into the git workflow design problem. The session was a great success: my existing design was able to meet nearly everyone's needs and wants. The room was obviously keen to see progress. The next stage was to deploy tag2upload. I spoke to various key people at the Debconf and afterwards in 2019 and the code has been basically ready since then. Unfortunately, deployment of tag2upload is mired in politics. It was blocked by a key team because of unfounded security concerns; positive opinions from independent security experts within Debian were disregarded. Of course it is always hard to get a team to agree to something when it's part of a transition plan which treats their systems as an obsolete setup retained for compatibility. Current status If you don't know about Debian's git packaging practices (eg, you have no idea what "patches-unapplied packaging branch without .pc directory" means), and don't want want to learn about them, you must use dgit to obtain the source of Debian packages. There is a lot more information and detailed instructions in dgit-user(7). Hopefully either the maintainer did the best thing, or, if they didn't, you won't need to inspect the history. If you are a Debian maintainer, you should use dgit push-source to do your uploads. This will make sure that users of dgit will see a reasonable git history.
edited 2021-09-15 14:48 Z to fix a typo


comment count unavailable comments

15 August 2021

Sean Whitton: Post hoc apt-listchanges

Yesterday I upgraded a machine from Debian buster to bullseye without apt-listchanges installed, oops. Here s a way to get new NEWS.Debian entries after the fact.
perl -MDpkg::Changelog::Debian -wE'$parser = Dpkg::Changelog::Debian->new;
    for (</usr/share/doc/*/NEWS.Debian*>)  
        $parser->load($_);
        $_->get_timepiece && $_->get_timepiece->year < 2020 ? last : say
            for $parser->@*  ' 2>&1   mail -s"News for $(hostname)" you@example.com

21 July 2021

Sean Whitton: Delivering Common Lisp executables using Consfigurator

I realised this week that my recent efforts to improve how Consfigurator makes the fork(2) system call have also created a way to install executables to remote systems which will execute arbitrary Common Lisp code. Distributing precompiled programs using free software implementations of the Common Lisp standard tends to be more of a hassle than with a lot of other high level programming languages. Executables will often be hundreds of megabytes in size even if your codebase is just a few megabytes, because the whole interactive Common Lisp environment gets bundled along with your program s code. Commercial Common Lisp implementations manage to do better, as I understand it, by knowing how to shake out unused code paths. Consfigurator s new mechanism uploads only changed source code, which might only be kilobytes in size, and updates the executable on the remote system. So it should be useful for deploying Common Lisp-powered web services, and the like. Here s how it works. When you use Consfigurator you define an ASDF system analagous to a Python package or Perl distribution called your consfig . This defines HOST objects to represent the machines that you ll use Consfigurator to manage, and any custom properties, functions those properties call, etc.. An ASDF system can depend upon other systems; for example, every consfig depends upon Consfigurator itself. When you execute Consfigurator deployments, Consfigurator uploads the source code of any ASDF systems that have changed since you last deployed this host, starts up Lisp on the remote machine, and loads up all the systems. Now the remote Lisp image is in a similarly clean state to when you ve just started up Lisp on your laptop and loaded up the libraries you re going to use. Only then are the actual deployment instructions are sent on stdin. What I ve done this week is insert an extra step for the remote Lisp image in between loading up all the ASDF systems and reading the deployment from stdin: the image calls fork(2) and establishes a pipe to communicate with the child process. The child process can be sent Lisp forms to evaluate, but for each Lisp form it receives it will actually fork again, and have its child process evaluate the form. Thus, going into the deployment, the original remote Lisp image has the capability to have arbitrary Lisp forms evaluated in a context in which all that has happened is that a statically defined set of ASDF systems has been loaded the child processes never see the full deployment instructions sent on stdin. Further, the child process responsible for actually evaluating the Lisp form received from the first process first forks off another child process and sets up its own control pipe, such that it too has the capacbility to have arbitrary Lisp forms evaluated in a cleanly loaded context, no matter what else it might put in its memory in the meantime. (Things are set up such that the child processes responsible for actually evaluating the Lisp forms never see the Lisp forms received for evaluation by other child processes, either.) So suppose now we have an ASDF system :com.silentflame.cool-web-service, and there is a function (start-server PORT) which we should call to start listening for connections. Then we can make our consfig depend upon that ASDF system, and do something like this:
CONSFIG> (deploy-these ((:ssh :user "root") :sbcl) server.example.org
           ;; Set up Apache to proxy requests to our service.
           (apache:https-vhost ...)
           ;; Now apply a property to dump the image.
           (image-dumped "/usr/local/bin/cool-web-service"
                         '(cool-web-service:start-server 1234)))
Consfigurator will: SSH to server.example.org; upload all the ASDF source for your consfig and its dependencies; compile and load that code into a remote SBCL process; call fork(2) and set up the control pipe; receive the applications of APACHE:HTTPS-VHOST and IMAGE-DUMPED shown above from your laptop, on stdin; apply the APACHE:HTTPS-VHOST property to ensure that Apache is proxying connections to port 1234; send a request into the control pipe to have the child process fork again and dump an executable which, when started, will evaluate the form (cool-web-service:start-server 1234). And that form will get evaluated in a pristine Lisp image, where the only meaningful things that have happened is that some ASDF systems have been loaded and a single fork(2) has taken place. You d probably need to add some other properties to add some mechanism for actually invoking /usr/local/bin/cool-web-service and restarting it when the executable is updated. (Background: The primary reason why Consfigurator s remote Lisp images need to call fork(2) is that they need to do things like setuid from root to other accounts and enter chroots without getting stuck in those contexts. Previously we forked right before entering such contexts, but that meant that Consfigurator deployments could never be multithreaded, because it might later be necessary to fork, and you can t usually do that once you ve got more than one thread running. So now we fork before doing anything else, so that the parent can then go multithreaded if desired, but can still execute subdeployments in contexts like chroots by sending Lisp forms to evaluate in those contexts into the control pipe.)

10 July 2021

Sean Whitton: Live replacement of provider cloud images with upstream Debian

Tonight I m provisioning a new virtual machine at Hetzner and I wanted to share how Consfigurator is helping with that. Hetzner have a Debian buster image you can start with, as you d expect, but it comes with things like cloud-init, preconfiguration to use Hetzner s apt mirror which doesn t serve source packages(!), and perhaps other things I haven t discovered. It s a fine place to begin, but I want all the configuration for this server to be explicit in my Consfigurator consfig, so it is good to start with pristine upstream Debian. I could boot one of Hetzner s installation ISOs but that s slow and manual. Consfigurator can replace the OS in the VM s root filesystem and reboot for me, and we re ready to go. Here s the configuration:
(defhost foo.silentflame.com (:deploy ((:ssh :user "root") :sbcl))
  (os:debian-stable "buster" :amd64)
  ;; Hetzner's Debian 10 image comes with a three-partition layout and boots
  ;; with traditional BIOS.
  (disk:has-volumes
   (physical-disk
    :device-file "/dev/sda" :boots-with '(grub:grub :target "i386-pc")))
  (on-change (installer:cleanly-installed-once
              nil
              ;; This is a specification of the OS Hetzner's image has, so
              ;; Consfigurator knows how to install SBCL and debootstrap(8).
              ;; In this case it's the same Debian release as the replacement.
              '(os:debian-stable "buster" :amd64))
    ;; Clear out the old OS's EFI system partition contents, in case we can
    ;; switch to booting with EFI at some point (if we wanted we could specify
    ;; an additional x86_64-efi target above, and grub-install would get run
    ;; to repopulate /boot/efi, but I don't think Hetzner can boot from it yet).
    (file:directory-does-not-exist "/boot/efi/EFI")
    (apt:installed "linux-image-amd64")
    (installer:bootloaders-installed)
    (fstab:entries-for-volumes
     (disk:volumes
       (mounted-ext4-filesystem :mount-point "/")
       (partition
        (mounted-fat32-filesystem
         :mount-options '("umask=0077") :mount-point "/boot/efi"))))
    (file:lacks-lines "/etc/fstab" "# UNCONFIGURED FSTAB FOR BASE SYSTEM")
    (file:is-copy-of "/etc/resolv.conf" "/old-os/etc/resolv.conf")
    (mount:unmounted-below-and-removed "/old-os"))
  (apt:mirror "http://ftp.de.debian.org/debian")
  (apt:no-pdiffs)
  (apt:standard-sources.list)
  (sshd:installed)
  (as "root" (ssh:authorized-keys +spwsshkey+))
  (sshd:no-passwords)
  (timezone:configured "Etc/UTC")
  (swap:has-swap-file "2G")
  (network:clean-/etc/network/interfaces)
  (network:static "enp1s0" "xxx.xxx.xxx.xxx" "xxx.xxx.1.1" "255.255.255.255"))
and to use it you evaluate this at the REPL:
CONSFIG> (deploy ((:ssh :user "root" :hop "xxx.xxx.xxx.xxx") :sbcl) foo.silentflame.com)
Here the :HOP parameter specifies the IP address of the new machine, as DNS hasn t been updated yet. Consfigurator installs SBCL and debootstrap(8), prepares a minimal system, replaces the contents of /, gets to work applying the other properties, and then reboots. This gets us a properly populated fstab:
UUID=...            /           ext4    relatime    0   1
PARTUUID=...        /boot/efi   vfat    umask=0077  0   2
/var/lib/swapfile   swap        swap    defaults    0   0
(slightly doctored for more readable alignment) There s ordering logic so that the swapfile will end up after whatever filesystem contains it; a UUID is used for ext4 filesystems, but for fat32 filesystems, to be safe, a PARTUUID is used. The application of (INSTALLER:BOOTLOADERS-INSTALLED) handles calling both update-grub(8) and grub-install(8), relying on the metadata specified about /dev/sda. Next time we execute Consfigurator against the machine, it ll ignore all the property applications attached to the application of (INSTALLER:CLEANLY-INSTALLED-ONCE) with ON-CHANGE, and just apply everything following that block. There are a few things I don t have good solutions for. When you boot Hetzner s image the primary network interface is eth0, but then for a freshly debootstrapped Debian you get enp1s0, and I haven t got a good way of knowing what it ll be (if you know it ll have the same name, you can use (NETWORK:PRESERVE-STATIC-ONCE) to create a file in /etc/network/interfaces.d based on the current default route and corresponding interface). Another tricky thing is SSH host keys. It s easy to use Consfigurator to add host keys to your laptop s ~/.ssh/known_hosts, but in this case the host key changes back and forth from whatever the Hetzner image has and the newly generated key you get afterwards. One option might be to copy the old host keys out of /old-os before it gets deleted, like how /etc/resolv.conf is copied. This work is based on Propellor s equivalent functionality. I think my approach to handling /etc/fstab and bootloader installation is an improvement on what Joey does.

20 June 2021

Sean Whitton: transient-caps-lock

If you re writing a lot of Common Lisp and you want to follow the convention of using all uppercase to refer to symbols in docstrings, comments etc., you really need something better than the shift key. Similarly if you re writing C and you have VARIOUS_LONG_ENUMS. The traditional way is a caps lock key. But that means giving up a whole keyboard key, all of the time, just for block capitalisation, which one hardly uses outside of programming. So a better alternative is to come up with some Emacs thing to get block capitalisation, as Emacs key binding is much more flexible than system keyboard layouts, and can let us get block capitalisation without giving up a whole key. The simplest thing would be to bind some sequence of keys to just toggle caps lock. But I came up with something a bit fancier. With the following, you can type M-C, and then you get block caps until the point at which you ve probably finished typing your symbol or enum name.
(defun spw/transient-caps-self-insert (&optional n)
  (interactive "p")
  (insert-char (upcase last-command-event) n))
(defun spw/activate-transient-caps ()
  "Activate caps lock while typing the current whitespace-delimited word(s).
This is useful for typing Lisp symbols and C enums which consist
of several all-uppercase words separated by hyphens and
underscores, such that M-- M-u after typing will not upcase the
whole thing."
  (interactive)
  (let* ((map (make-sparse-keymap))
     (deletion-commands &apos(delete-backward-char
                          paredit-backward-delete
                          backward-kill-word
                          paredit-backward-kill-word
                          spw/unix-word-rubout
                          spw/paredit-unix-word-rubout))
     (typing-commands (cons &aposspw/transient-caps-self-insert
                            deletion-commands)))
     (substitute-key-definition &aposself-insert-command
                                #&aposspw/transient-caps-self-insert
                                map
                                (current-global-map))
    (set-transient-map
     map
     (lambda ()
       ;; try to determine whether we are probably still about to try to type
       ;; something in all-uppercase
       (and (member this-command typing-commands)
            (not (and (eq this-command &aposspw/transient-caps-self-insert)
                      (= (char-syntax last-command-event) ?\ )))
            (not (and (or (bolp) (= (char-syntax (char-before)) ?\ ))
                      (member this-command deletion-commands))))))))
(global-set-key "\M-C" #&aposspw/activate-transient-caps)
A few notes:

15 May 2021

Sean Whitton: pinebookpro

I recently bought a Pinebook Pro. This was mainly out of general interest, but also because I wanted to have a spare portable computer. When I was recently having some difficulty with my laptop not charging, I realised that I am dependent on having access to Emacs, notmuch.el and my usual git repositories in the way that most people are dependent on their smartphones all the info I need to get things done is in there, and it s very disabling not to have it. So, good to have a spare. I decided to get the machine running the hard way, and have been working to add a facility to install the device-specific bootloader to Consfigurator. It has been good to learn about how ARM machines boot. The only really hard part turned out to be coming up with the right abstractions within Consfigurator, thanks to the hard work of the Debian U-Boot maintainers. This left me with a chroot and a corresponding disk image, properly partitioned and with the bootloader installed. It was only then that the difficulties began: getting a kernel and initrd combination which can output to the Pinebook Pro s screen and take input from its keyboard is not really straightforward yet, but that s required for inputting disk encryption passwords, which are required on portable devices. I don t have the right hardware to make a serial connection to the machine, so all this took a lot of trial and error. I ve ended up using Manjaro s patched upstream kernel build for now, because that compiles in the right drivers, and debugging an initrd without a serial connection is far too inefficient. What I keep having to remind myself is that this device isn t really a laptop in the usual sense it s a single board computer that s powering several pieces of hardware which together roughly constitute a laptop. I think something which epitomises this is how the power light doesn t come on when you hit the power button, but only when the bootloader or operating system kernel thinks to turn on the LED. You start up this SBC and it loads up some software and then once it has got itself going several seconds later that software starts turning on the screen, keyboard, power LEDs etc. Whereas on an ordinary laptop it s more than you turn on the keyboard, screen, power LEDs etc. all at once, and then /they/ go off and load some software. Of course this description is nothing like what s actually going on, but it s my attempt to capture how it feels as a user, who is installing operating systems, but otherwise treating the laptop s hardware, including things like boot ROMs, as a black box. There are tangible differences between what it is like to do that with an ordinary laptop and with the Pinebook Pro. Thanks to Vagrant Cascadian for all the work on U-Boot in Debian and for help on IRC, Cyril Brulebois for help with crossbuilding, and Birger Schacht for a useful blog post.

28 April 2021

Russell Coker: Links April 2021

Dr Justin Lehmiller s blog post comparing his official (academic style) and real biographies is interesting [1]. Also the rest of his blog is interesting too, he works at the Kinsey Institute so you know he s good. Media Matters has an interesting article on the spread of vaccine misinformation on Instagram [2]. John Goerzen wrote a long post summarising some of the many ways of having a decentralised Internet [3]. One problem he didn t address is how to choose between them, I could spend months of work to setup a fraction of those services. Erasmo Acosta wrote an interesting medium article Could Something as Pedestrian as the Mitochondria Unlock the Mystery of the Great Silence? [4]. I don t know enough about biology to determine how plausible this is. But it is a worry, I hope that humans will meet extra-terrestrial intelligences at some future time. Meredith Haggerty wrote an insightful Medium article about the love vs money aspects of romantic comedies [5]. Changes in viewer demographics would be one factor that makes lead actors in romantic movies significantly less wealthy in recent times. Informative article about ZIP compression and the history of compression in general [6]. Vice has an insightful article about one way of taking over SMS access of phones without affecting voice call or data access [7]. With this method the victom won t notice that they are having their sservice interfered with until it s way too late. They also explain the chain of problems in the US telecommunications industry that led to this. I wonder what s happening in this regard in other parts of the world. The clown code of ethics (8 Commandments) is interesting [8]. Sam Hartman wrote an insightful blog post about the problems with RMS and how to deal with him [9]. Also Sam Whitton has an interesting take on this [10]. Another insightful post is by Selam G about RMS long history of bad behavior and the way universities are run [11]. Cory Doctorow wrote an insightful article for Locus about free markets with a focus on DRM on audio books [12]. We need legislative changes to fix this!

8 April 2021

Sean Whitton: consfigurator-live-build

One of my goals for Consfigurator is to make it capable of installing Debian to my laptop, so that I can stop booting to GRML and manually partitioning and debootstrapping a basic system, only to then turn to configuration management to set everything else up. My configuration management should be able to handle the partitioning and debootstrapping, too. The first stage was to make Consfigurator capable of debootstrapping a basic system, chrooting into it, and applying other arbitrary configuration, such as installing packages. That s been in place for some weeks now. It s sophisticated enough to avoid starting up newly installed services, but I still need to add some bind mounting. Another significant piece is teaching Consfigurator how to partition block devices. That s quite tricky to do in a sufficiently general way I want to cleanly support various combinations of LUKS, LVM and regular partitions, including populating /etc/crypttab and /etc/fstab. I have some ideas about how to do it, but it ll probably take a few tries to get the abstractions right. Let s imagine that code is all in place, such that Consfigurator can be pointed at a block device and it will install a bootable Debian system to it. Then to install Debian to my laptop I d just need to take my laptop s disk drive out and plug it into another system, and run Consfigurator on that system, as root, pointed at the block device representing my laptop s disk drive. For virtual machines, it would be easy to write code which loop-mounts an empty disk image, and then Consfigurator could be pointed at the loop-mounted block device, thereby making the disk image file bootable. This is adequate for virtual machines, or small single-board computers with tiny storage devices (not that I actually use any of those, but I want Consfigurator to be able to make disk images for them!). But it s not much good for my laptop. I casually referred to taking out my laptop s disk drive and connecting it to another computer, but this would void my laptop s warranty. And Consfigurator would not be able to update my laptop s NVRAM, as is needed on UEFI systems. What s wanted here is a live system which can run Consfigurator directly on the laptop, pointed at the block device representing its physical disk drive. Ideally this live system comes with a chroot with the root filesystem for the new Debian install already built, so that network access is not required, and all Consfigurator has to do is partition the drive and copy in the contents of the chroot. The live system could be set up to automatically start doing that upon boot, but another option is to just make Consfigurator itself available to be used interactively. The user boots the live system, starts up Emacs, starts up Lisp, and executes a Consfigurator deployment, supplying the block device representing the laptop s disk drive as an argument to the deployment. Consfigurator goes off and partitions that drive, copies in the contents of the chroot, and executes grub-install to make the laptop bootable. This is also much easier to debug than a live system which tries to start partitioning upon boot. It would look something like this:
    ;; melete.silentflame.com is a Consfigurator host object representing the
    ;; laptop, including information about the partitions it should have
    (deploy-these :local ...
      (chroot:partitioned-and-installed
        melete.silentflame.com "/srv/chroot/melete" "/dev/nvme0n1"))
Now, building live systems is a fair bit more involved than installing Debian to a disk drive and making it bootable, it turns out. While I want Consfigurator to be able to completely replace the Debian Installer, I decided that it is not worth trying to reimplement the relevant parts of the Debian Live tool suite, because I do not need to make arbitrary customisations to any live systems. I just need to have some packages installed and some files in place. Nevertheless, it is worth teaching Consfigurator how to invoke Debian Live, so that the customisation of the chroot which isn t just a matter of passing options to lb_config(1) can be done with Consfigurator. This is what I ve ended up with in Consfigurator s source code:
(defpropspec image-built :lisp (config dir properties)
  "Build an image under DIR using live-build(7), where the resulting live
system has PROPERTIES, which should contain, at a minimum, a property from
CONSFIGURATOR.PROPERTY.OS setting the Debian suite and architecture.  CONFIG
is a list of arguments to pass to lb_config(1), not including the '-a' and
'-d' options, which Consfigurator will supply based on PROPERTIES.
This property runs the lb_config(1), lb_bootstrap(1), lb_chroot(1) and
lb_binary(1) commands to build or rebuild the image.  Rebuilding occurs only
when changes to CONFIG or PROPERTIES mean that the image is potentially
out-of-date; e.g. if you just add some new items to PROPERTIES then in most
cases only lb_chroot(1) and lb_binary(1) will be re-run.
Note that lb_chroot(1) and lb_binary(1) both run after applying PROPERTIES,
and might undo some of their effects.  For example, to configure
/etc/apt/sources.list, you will need to use CONFIG not PROPERTIES."
  (:desc (declare (ignore config properties))
         #?"Debian Live image built in $ dir ")
  (let* (...)
    ;; ...
     (eseqprops
      ;; ...
      (on-change
          (eseqprops
           (on-change
               (file:has-content ,auto/config ,(auto/config config) :mode #o755)
             (file:does-not-exist ,@clean)
             (%lbconfig ,dir)
             (%lbbootstrap t ,dir))
           (%lbbootstrap nil ,dir)
           (deploys ((:chroot :into ,chroot)) ,host))
        (%lbchroot ,dir)
        (%lbbinary ,dir)))))
Here, %lbconfig is a property running lb_config(1), %lbbootstrap one which runs lb_bootstrap(1), etc. Those properties all just change directory to the right place and run the command, essentially, with a little extra code to handle failed debootstraps and the like. The ON-CHANGE and ESEQPROPS combinators work together to sequence the interaction of the Debian Live suite and Consfigurator. This way, we only rebuild the chroot if the configuration changed, and we only rebuild the image if the chroot changed. Now over in my personal consfig:
(try-register-data-source
 :git-snapshot :name "consfig" :repo #P"src/cl/consfig/" ...)
(defproplist hybrid-live-iso-built :lisp ()
  "Build a Debian Live system in /srv/live/spw.
Typically this property is not applied in a DEFHOST form, but rather run as
needed at the REPL.  The reason for this is that otherwise the whole image will
get rebuilt each time a commit is made to my dotfiles repo or to my consfig."
  (:desc "Sean's Debian Live system image built")
  (live-build:image-built.
      '("--archive-areas" "main contrib non-free" ...)
      "/srv/live/spw"
    (os:debian-stable "buster" :amd64)
    (basic-props)
    (apt:installed "whatever" "you" "want")
    (git:snapshot-extracted "/etc/skel/src" "dotfiles")
    (file:is-copy-of "/etc/skel/.bashrc" "/etc/skel/src/dotfiles/.bashrc")
    (git:snapshot-extracted "/root/src/cl" "consfig")))
The first argument to LIVE-BUILD:IMAGE-BUILT. is additional arguments to lb_config(1). The third argument onwards are the properties for the live system. The cool thing is GIT:SNAPSHOT-EXTRACTED the calls to this ensure that a copy of my Emacs configuration and my consfig end up in the live image, ready to be used interactively to install Debian, as described above. I ll need to add something like (chroot:host-chroot-bootstrapped melete.silentflame.com "/srv/chroot/melete") too. As with everything Consfigurator-related, Joey Hess s Propellor is the giant upon whose shoulders I m standing.

23 March 2021

Sean Whitton: rmsopenletter

I was shocked to learn today that Richard Stallman has been reinstated as a member of the board of the Free Software Foundation. I think this is plain inappropriate, but I cannot see how anyone who doesn t think that could fail to see the reinstatement as counterproductive. As Bradley M. Kuhn put it,
The question is whether an organization should have a designated leader who is on a sustained, public campaign advocating about an unrelated issue that many consider controversial. It really doesn t matter what your view about the controversial issue is; a leader who refuses to stop talking loudly about unrelated issues eventually creates an untenable distraction from the radical activism you re actively trying to advance. The message of universal software freedom is a radical cause; it s basically impossible for one individual to effectively push forward two unrelated controversial agendas at once. In short, the radical message of software freedom became overshadowed by RMS radical views about sexual morality.
There is an open letter calling for the removal of the entire Board of the Free Software Foundation in response. I haven t signed the letter because the Free Software Foundation Board s vote to reinstate Stallman was not unanimous, so the call to remove all of them does not make sense to me. I agree with the open letter s call to remove Stallman from other positions of leadership. I hope that this whole situation can be resolved quickly.

13 March 2021

Sean Whitton: lisp-use-for-transpose-chars

I had thought that Emacs C-t was mainly about correcting typos. It turns out to be extremely useful when working on Lisp macros which themselves write macros. This typically involves nested quasiquotation, where you can have multiple alternating sequences of open parentheses and backticks, or of commas, quotation marks and ampersats. While you re working on it you often need to reorder these character sequences and C-t does a great job.

10 March 2021

Sean Whitton: consfigurator 0.3.1

I d like to briefly introduce my new project, Consfigurator:
Consfigurator is a system for declarative configuration management using Common Lisp. You can use it to configure hosts as root, deploy services as unprivileged users, build and deploy containers, and produce disc images. [not all of these are implemented yet, but the design permits them to be] Consfigurator s design gives you a great deal of flexibility about how to control the hosts you want to configure. If there is a command you can run which will obtain input and output streams attached to an interactive POSIX sh running on the target host/container, then with a little glue code, you can use much of Consfigurator s functionality to configure that host/container. But if it is possible to get an implementation of Common Lisp started up on the host, then Configurator can transparently execute your deployment code over on the remote side, rather than exchanging information via POSIX sh. This lets you use the full power of Common Lisp to deploy your configuration. Configurator has convenient abstractions for combining these different ways to execute your configuration on hosts with different ways of connecting to them. Connections can be arbitrarily nested. For example, to combine SSHing to a Debian machine as an unprivileged user, using sudo to become root, and then starting up a Lisp image to execute your deployment code, you would evaluate
    (deploy ((:ssh (:sudo :as "spwhitton@athena.example.com") :debian-sbcl)) athena.example.com)
Declarative configuration management systems like Consfigurator and Propellor share a number of goals with projects like the GNU Guix System and NixOS. However, tools like Consfigurator and Propellor try to layer the power of declarative and reproducible configuration on top of traditional, battle-tested unix system administration infrastructure like apt, dpkg, yum, and distro package archives, rather than seeking to replace any of those. Let s get as much as we can out of all that existing distro policy-compliant work!
Please check out the user s manual, which includes a tutorial/quick start guide, and come join us in #consfigurator on irc.oftc.net. It s early days but you can already do a fair few things with Consfigurator. It s a good time to come help get all the basic properties defined!

4 March 2021

Sean Whitton: waylandmar21

While struggling with Pfizer second dose side effects yesterday, with little ability to do anything serious so surreal to have a fever yet also certainty you re not actually ill[1] I thought I d try building the branch of Emacs with native Wayland support, and try starting up Sway instead of i3. I recently upgraded my laptop to Debian bullseye, as I usually do at this stage of our pre-release freeze, and was wondering whether bullseye would be the release which would enable me to switch to Wayland. Why might I want to do this? I don t care about screen tearing and don t have any fancy monitors with absurd numbers of pixels. Previously, I had been hoping to cling on to my X11 setup for as long as possible, and switch to Wayland only once things I want to use started working worse on X11, because all the developers of those things have stopped using X11. But then after upgrading to bullseye, I found I had to forward-port an old patch to xfce4-session to prevent it from resetting SSH_AUTH_SOCK to the wrong value, and I thought to myself, maybe I could cut out some of the layers here, and maybe it ll be a bit less annoying. I have a pile of little scripts trying to glue together xfce4 and i3 to get all the functionality I need, but since there have been people who use their computers for similar purposes to me trying to make Sway useful for quite some time now, maybe there are more integrated solutions available. I have also been getting tired of things which have only ever half-worked under X, like toggling autolock off when there isn t fullscreen video playing (when I m video conferencing on another device, I often want to prevent my laptop s screen from locking, and it works most of the time, but sometimes still locks, sigh). I have a normalise desktop keybinding which tries to fix recurrent issues by doing things like restarting ibus, and it would be nice to drop something so hackish. And indeed, a lot of basic things do work way better under Sway. swayidle is clean and sane, and I was easily able to add a keybinding which inhibits locking the screen when a certain window is visible. I could bind brightness up/down keys without having to invoke xfce4-power-manager never managed that before and, excitingly, I could have those keys bound such that they still work when the screen is locked. I still need two old scripts which interact with the i3/sway IPC, but those two are reasonable ways to extend functionality, rather than bad hacks. The main thing that I could not figure out is IME various people claim online to have got typing their Asian languages working natively under Sway, not just into Xwayland windows, but I couldn t, and there is no standard way to do it yet, it would seem. Also, it seems Qt in Debian doesn t support Wayland natively, so far as I could tell. And there isn t really a drop-in replacement for dmenu yet, so you have to run that under Xwayland. A lot of this is probably going to be fixed during 2021, but the thing is, I ll be on Debian bullseye, so how it works now is probably as good as it is going to get for the next two years or so. So, wanting to get back to doing something more useful today, I reluctantly booted back into X11. I m really looking forward to switching to Sway, and getting rid of some of my hacks, but I think I am probably going to have to wait for Debian bookworm unless I completely run out of patience with the various X11 annoyances described above, and start furiously backporting things. Update, later that afternoon Newer versions of fcitx5 packages hit Debian testing within the past few days, it turns out, and the IME problem is solved! So looks like I am slowly going to be able to migrate to Sway during the Debian bullseye lifecycle after all. How nice. Many thanks to various upstreams and those who have been working on these packages in Debian. [1] Okay, I suppose I could have caught the disease a few days ago and it became symptomatic at the same time I was experiencing the side effects.

31 January 2021

Sean Whitton: gemini:// space

Recently I have become curious about the Gemini Project and the content that people have made available to be retrieved over the gemini:// protocol. I m not convinced by the arguments for not just using http, and mostly it s just that I typically find more things that I am interested in casually reading through on people s gemlogs than I would on, say, reddit, and similar aggregators. But presumably advocates of gemini:// and the text/gemini format would argue that it s various respects in which it differs from the web that makes geminispace conducive to the production of the sort of content you find there. So I m remaining open minded about the possibility that having a completely separate protocol is important, and not just an annoyance because rss2email doesn t work and I had to spend time writing gmi2email. I now have a games console at home for the first time in some years, which I bought in response to the ongoing pandemic, and one thing that I have noticed is that using it feels like being offline in a way that playing games on a regular computer never would. It has a WiFi connection but it doesn t have a web browser, and I am glad that using it provides an opportunity to be disconnected from the usual streams of information. And perhaps something similar ought to be said in favour of how the Gemini project does not just use http. There is, perhaps, a positive psychological effect induced by making the boundary between text/gemini and the web as hard as it is made by using gemini:// rather than http. Something about which I find myself much more sceptical is how the specification for gemini:// and text/gemini is not extensible. Advocates of Gemini have this idea that they can t include, say, a version number in the protocol, because the extensibility of the web is what has led to the problems they think it has, so they want to make it impossible. Now on the one hand perhaps the people behind Gemini are in the best position that anyone is in to come up with a spec which they will finalise and render effectively unchangeable, because a lot of them have been using Gopher for decades, and so they have enough experience to be able to say exactly what Gopher is missing, and be confident that they ve not missed anything. But on the other hand, Gemini is one technological piece in attempts to make a version of the Internet which is healthier for humans the so-called small Internet movement and maybe there will be new ideas about how the small Internet should be which would benefit from a new version of the Gemini specification. So it seems risky to lock-in to one version. Comments on Hacker News.

8 November 2020

Sean Whitton: Combining repeat and repeat-complex-command

In Emacs, you can use C-x z to repeat the last command you input, and subsequently you can keep tapping the z key to execute that command again and again. If the command took minibuffer input, however, you ll be asked for that input again. For example, suppose you type M-z : to delete through the next colon character. If you want to keep going and delete through the next few colons, you would need to use C-x z : z : z : etc. which is pretty inconvenient. So there s also C-x ESC ESC RET or C-x M-: RET, which will repeat the last command which took minibuffer input, as if you d given it the same minibuffer input. So you could use M-z : C-x M-: RET C-x M-: RET etc., but then you might as well just keep typing M-z : over and over. It s also quite inconvenient to have to remember whether you need to use C-x z or C-x M-: RET. I wanted to come up with a single command which would choose the correct repetition method. It turns out it s a bit involved, but here s what I came up with. You can use this under the GPL-3 or any later version published by the FSF. Assumes lexical binding is turned on for the file you have this in.
;; Adapted from  repeat-complex-command&apos as of November 2020
(autoload &aposrepeat-message "repeat")
(defun spw/repeat-complex-command-immediately (arg)
  "Like  repeat-complex-command&apos followed immediately by RET."
  (interactive "p")
  (if-let ((newcmd (nth (1- arg) command-history)))
      (progn
        (add-to-history &aposcommand-history newcmd)
        (repeat-message "Repeating %S" newcmd)
        (apply #&aposfuncall-interactively
               (car newcmd)
               (mapcar (lambda (e) (eval e t)) (cdr newcmd))))
    (if command-history
        (error "Argument %d is beyond length of command history" arg)
      (error "There are no previous complex commands to repeat"))))
(let (real-last-repeatable-command)
  (defun spw/repeat-or-repeat-complex-command-immediately ()
    "Call  repeat&apos or  spw/repeat-complex-command-immediately&apos as appropriate.

Note that no prefix argument is accepted because this has
different meanings for  repeat&apos and for
 spw/repeat-complex-command-immediately&apos, so that might cause surprises."
    (interactive)
    (if (eq last-repeatable-command this-command)
        (setq last-repeatable-command real-last-repeatable-command)
      (setq real-last-repeatable-command last-repeatable-command))
    (if (eq last-repeatable-command (caar command-history))
        (spw/repeat-complex-command-immediately 1)
      (repeat nil))))
;;  suspend-frame&apos is bound to both C-x C-z and C-z
(global-set-key "\C-z" #&aposspw/repeat-or-repeat-complex-command-immediately)

29 August 2020

Jelmer Vernooij: Debian Janitor: The Slow Trickle from Git Repositories to the Debian Archive

The Debian Janitor is an automated system that commits fixes for (minor) issues in Debian packages that can be fixed by software. It gradually started proposing merges in early December. The first set of changes sent out ran lintian-brush on sid packages maintained in Git. This post is part of a series about the progress of the Janitor. Last week s blog post documented how there are now over 30,000 lintian issues that have been fixed in git packaging repositories by the Janitor. It's important to note that any fixes from the Janitor that make it into a Git packaging repository will also need to be uploaded to the Debian archive. This currently requires that a Debian packager clones the repository and builds and uploads the package. Until a change makes it into the archive, users of Debian will unfortunately not see the benefits of improvements made by the Janitor. 82% of the 30,000 changes from the Janitor that have made it into a Git repository have not yet been uploaded, although changes do slowly trickle in as maintainers make other changes to packages and upload them along with the lintian fixes from the Janitor. This is not just true for changes from the Janitor, but for all sorts of other smaller improvements as well. However, the process of cloning and building git repositories and uploading the resulting packages to the Debian archive is fairly time-consuming and it s probably not worth the time of developers to follow up every change from the Janitor with a labour-intensive upload to the archive. It would be great if it was easier to trigger uploads from git commits. Projects like tag2upload will hopefully help, and make it more likely that changes end up in the Debian archive. The majority packages do get at least one new source version upload per release, so most changes will eventually make it into the archive.

For more information about the Janitor's lintian-fixes efforts, see the landing page.

23 July 2020

Sean Whitton: keyboardingupdates

Marks and mark rings in GNU Emacs I recently attempted to answer the question of whether experienced Emacs users should consider partially or fully disabling Transient Mark mode, which is (and should be) the default in modern GNU Emacs. That blog post was meant to be as information-dense as I could make it, but now I d like to describe the experience I have been having after switching to my custom pseudo-Transient Mark mode, which is labelled mitigation #2 in my older post. In summary: I feel like I ve uncovered a whole editing paradigm lying just beneath the surface of the editor I ve already been using for years. That is cool and enjoyable in itself, but I think it s also helped me understand other design decisions about the basics of the Emacs UI better than before in particular, the ideas behind how Emacs chooses where to display buffers, which were very frustrating to me in the past. I am now regularly using relatively obscure commands like C-x 4 C-o. I see it! It all makes sense now! I would encourage everyone who has never used Emacs without Transient Mark mode to try turning it off for a while, either fully or partially, just to see what you can learn. It s fascinating how it can come to seem more convenient and natural to pop the mark just to go back to the end of the current line after fixing up something earlier in the line, even though doing so requires pressing two modified keys instead of just C-e. Eshell I was amused to learn some years ago that someone was trying to make Emacs work as an X11 window manager. I was amazed and impressed to learn, more recently, that the project is still going and a fair number of people are using it. Kudos! I suspect that the basic motivation for such projects is that Emacs is a virtual Lisp machine, and it has a certain way of managing visible windows, and people would like to be able to bring both of those to their X11 window management. However, I am beginning to suspect that the intrinsic properties of Emacs buffers are tightly connected to the ways in which Emacs manages visible windows, and the intrinsic properties of Emacs buffers are at least as fundamental as its status as a virtual Lisp machine. Thus I am not convinced by the idea of trying to use Emacs ways of handling visible windows to handle windows which do not contain Emacs buffers. (but it s certainly nice to learn it s working out for others) The more general point is this. Emacs buffers are as fundamental to Emacs as anything else is, so it seems unlikely to be particularly fruitful to move something typically done outside of Emacs into Emacs, unless that activity fits naturally into an Emacs buffer or buffers. Being suited to run on a virtual Lisp machine is not enough. What could be more suited to an Emacs buffer, however, than a typical Unix command shell session? By this I mean things like running commands which produce text output, and piping this output between commands and into and out of files. Typically the commands one enters are sort of like tiny programs in themselves, even if there are no pipes involved, because you have to spend time determining just what options to pass to achieve what you want. It is great to have all your input and output available as ordinary buffer text, navigable just like all your other Emacs buffers. Full screen text user interfaces, like top(1), are not the sort of thing I have in mind here. These are suited to terminal emulators, and an Emacs buffer makes a poor terminal emulator what you end up with is a sort of terminal emulator emulator. Emacs buffers and terminal emulators are just different things. These sorts of thoughts lead one to Eshell, the Emacs Shell. Quoting from its documentation:
The shell s role is to make [system] functionality accessible to the user in an unformed state. Very roughly, it associates kernel functionality with textual commands, allowing the user to interact with the operating system via linguistic constructs. Process invocation is perhaps the most significant form this takes, using the kernel s fork' andexec functions. Emacs is a user application, but it does make the functionality of the kernel accessible through an interpreted language namely, Lisp. For that reason, there is little preventing Emacs from serving the same role as a modern shell. It too can manipulate the kernel in an unpredetermined way to cause system changes. All it s missing is the shell-ish linguistic model.
Eshell has been working very well for me for the past month or so, for, at least, Debian packaging work, which is very command shell-oriented (think tools like dch(1)). The other respects in which Eshell is tightly integrated with the rest of Emacs are icing on the cake. In particular, Eshell can transparently operate on remote hosts, using TRAMP. So when I need to execute commands on Debian s ftp-master server to process package removal requests, I just cd /ssh:fasolo: in Eshell. Emacs takes care of disconnecting and connecting to the server when needed there is no need to maintain a fragile SSH connection and a shell process (or anything else) running on the remote end. Or I can cd /ssh:athena\ sudo:root@athena: to run commands as root on the webserver hosting this blog, and, again, the text of the session survives on my laptop, and may be continued at my leisure, no matter whether athena reboots, or I shut my laptop and open it up again the next morning. And of course you can easily edit files on the remote host.

Sean Whitton: Kinesis Advantage 2 for heavy Emacs users

A little under two months ago I invested in an expensive ergonomic keyboard, a Kinesis Advantage 2, and set about figuring out how to use it most effectively with Emacs. The default layout for the keyboard is great for strong typists who control their computer mostly with their mouse, but less good for Emacs users, who are strong typists that control their computer mostly with their keyboard. It took me several tries to figure out where to put the ctrl, alt, backspace, delete, return and spacebar keys, and aside from one forum post I ran into, I haven t found anyone online who came up with anything much like what I ve come up with, so I thought I should probably write up a blog post. The mappings Sequences of two modified keys on different halves of the keyboard It is desirable to input sequences like C-x C-o without switching which hand is holding the control key. This requires one-handed chording, but this is trecherous when the modifier keys not under the thumbs, because you might need to press the modified key with the same finger that s holding the modifier! Fortunately, most or all sequences of two keys modified by ctrl or alt/meta, where each of the two modifier keys is typed by a different hand, begin with C-c, C-x or M-g, and the left hand can handle each of these on its own. This leaves the right hand completely free to hit the second modified key while the left hand continues to hold down the modifier. My rebindings for ordinary keyboards I have some rebindings to make Emacs usage more ergonomic on an ordinary keyboard. So far, my Kinesis Advantage setup is close enough to that setup that I m not having difficulty switching back and forth from my laptop keyboard. The main difference is for sequences of two modified keys on different halves of the keyboard which of the two modified keys is easiest to type as a one-handed chord is different on the Kinesis Advantage than on my laptop keyboard. At this point, I m executing these sequences without any special thought, and they re rare enough that I don t think I need to try to determine what would be the most ergonomic way to handle them.

5 June 2020

Sean Whitton: spacecadetrebindings

I ve been less good at taking adequate typing breaks during the lockdown and I ve become concerned about how much chording my left hand does on its own during typical Emacs usage, with caps lock rebound to control, as I ve had it for years. I thought that now was as good a time as any to do something drastic about this. Here are my rebindings: Optional extras: This has the following advantages: The main disadvantage, aside from an adjustment period when I feel that someone has inserted a massive marshmellow between me and my computer, is that Ctrl-Alt combinations are a bit difficult; in Emacs, C-M-SPC is hard to do without. However I think I ve found a decent way to do it (thumb on control, curled ring finger on alt, possibly little finger on shift for Emacs infamous C-M-S-v standard binding).

Next.