Last year I purchased an e-bike upgrade kit for my mother in law. We decided to install it on a bicycle she originally bought back in the 80s, which I fixed and refurbished a couple of years ago and used until September 2022 when I bought myself a Dutch Cortina U4. When I used this bicycle, I installed a lightweight Shutter Precision dynamo hub and compatible lights, XLC at the front, B chel at the back. Unfortunately, since Swytch is a front wheel with a built-in electric motor, these lights don t have a dynamo to connect to anymore, and Swytch doesn t have a dedicated connector for lights. I tried asking the manufacturer for more documentation or schematics, but they refused to do so. Luckily, a Canadian member of the Pedelecs forum managed to reverse-engineer the Swytch connector pinouts, which gave me an idea on how to proceed. Unfortunately, that meant that I had to replace both lights, and by trial and error I found specific models that worked. Before the Axa lights, I also tried B chel s Tivoli e-bike light, but it didn t work because the voltage was too low:

B chel Tivoli light that didn t work

Once I knew what to do, the rest was super easy So, here we go:

1. Get a 3-pin (yellow) male connector with a cable, e.g. off AliExpress. Only two wires will be used, the white one is +4.2V (4-point-2, not 42!), the black one is earth. This will go into the throttle port. If you actually have a throttle, you need some sort of Y-splitter, but I don t, so this was not an issue for me. (However, I bought both sides (M and F), just to be sure.)

   Cable for the throttle port

2. Purchase an Axa 606 E6-48 front light. The 606 comes in two versions, for dynamos and e-bikes, use the one for e-bikes; despite being officially rated as 6 48V, these lights work quite well off 4.2V too.

   Axa 606 E6-48 light

3. Purchase an Axa Spark Steady rear light. This light works with both AC and DC (just like the 606, the official rating is 6 48V), and works off 4.2V without an issue.

   Axa Spark light

4. Wire lights up. I used tiny wire terminals to join the wires, but I m sure there are better options too. Insulate them well, make sure the red wire from the throttle connector is insulated too. I used a bunch of shrink tubes and black insulation tape. Since the voltage is not wildly different from what the dynamo hub produced (although AC, not DC), I was able to reuse the cable I had already routed to the rear carrier.
5. Lights go on automatically as soon as you touch the power button on the battery pack, and stay on until the battery pack is switched off completely. I was considering adding a handlebar switch, but since I lost the only one I had, I had to do without.

Front light

Rear light

The side effect of using the Axa Spark at the rear is that it has a capacitor inside and keeps going for a couple more minutes after the battery pack is off I haven t decided whether that s a benefit or a drawback

My attempt to travel to the UK by train last year didn t go quite as well as I expected. As I mentioned in that blog post, the NightJet to Brussels was cancelled, forcing me to fly instead. This disappointed me so much that I actually unpublished the blog post minutes after it was originally put online. The timing was nearly perfect: I type make publish and I get an email from BB saying they don t know if my train is going to run. Of course it didn t, as Deutsche Bahn workers went ahead with their strike. The blog post sat in the drafts for more than half a year until yesterday, when I finally updated and published it. The reason I have finally published it is that I m going to the UK by train once again. Now, unless railways decide to hold a strike again, fully by train both ways. Very expensive, especially compared to the price of Ryanair flights to my destination. Unfortunately, even though Eurostar added more daily services, they re still not cheap, especially on a shorter notice. This seems to apply to the BB s NightJet even more: I tried many routes between Vienna and London, and the cheapest still seemed to be the connection through Brussels. While researching the prices of the tickets, it seems all booking systems decided to stop co-operating. The Trainline refused to let me look up any trains at all, even with all tracking and advertisement allowed, SNCF kepts showing me overly generic errors (Sorry, an error has occurred.), while the GWR booking system kept crashing with a 500 Internal Server Error for about two hours.

Trainline, GWR and SNCF kept crashing

Eventually, having spent a lot of time and money, I ve booked my trains to, within and back from England. This time, Cambridge is among the destinations.

The complete route

Date	Station	Arrival	Departure	Train
26.4	Bratislava hl.st.		18:37	REX 2529
	Wien Hbf	19:44	20:13	NJ 40490
27.4	Bruxelles-Midi	9:54	15:56	EST 9145
	London St Pancras	17:01	17:43	ThamesLink
	Cambridge	18:43

I m not sure about it yet, but I may end up taking an earlier train from Bratislava just to ensure there s enough time for the change in Vienna; similarly, I m not sure how much time I will be spending at St Pancras, so I may take one of the later trains. P.S. The maps in this and other posts were created using uMap; the map data come from OpenStreetMap. The train route visualisation was generated with help of signal.eu.org.

This post was written in August 2021. Just as I was going to publish it, I received an email from BB stating that due to a railway strike in Germany my night train would be cancelled. Since the rest of the trip has already been booked well in advance, I had to take a plane to Charleroi and a bus to Brussels to catch my Eurostar. Ultimately, I ended up publishing it in April 2022, just as I m about to leave for a fully train-powered trip to the UK once again. Before the pandemic started, I planned to use the last months of my then-expiring UK visa and go to England by train. I ve completed two train long journeys by that time already, to Brussels and to Belarus and Ukraine, but this would be something quite different, as I wanted to have multiple stops on my way, use night trains where it made sense, and to go through the Channel Tunnel. The Channel Tunnel fascinated me since my childhood; I first read about it in the Soviet Science and Life magazine ( ) when I was seven. I ve never had the chance to use it though, since to board any train going though it I d first need to get to France, Belgium or the Netherlands, making it significantly more expensive than the cheap 30 Ryanair flights to Stansted. As the coronavirus spread across the world, all of my travel plans along with plans for a sabbatical had to be cancelled. During 2020, I only managed to go on two weekend trips to Prague and Budapest, followed by a two-weeks holiday on Crete (we returned just a couple of weeks before the infection numbers rose and lockdowns started). I do realise that a lot of people couldn t even have this much because the situation in their countries was much worse we were lucky to have had at least some travel. Fast forward to August 2021, I m fully vaccinated, I once again have a UK visa for five years, and the UK finally recognises the EU vaccination passports yay! I can finally go to Devon to see my mother and sister again. By train, of course. Compared to my original plan, this journey will be different: about the same or even more expensive than I originally planned, but shorter and with fewer stops on the way. My original plan would be to take multiple trains from Bratislava to France or Belgium and complete this segment of the trip in about three days, enjoying my stay in a couple of cities on the way. Instead, I m taking a direct NightJet from Vienna to Brussels, not stopping anywhere on the way.

Train route from Bratislava to Brussels

Since I was booking my trip just two weeks ahead, the price of the ticket is not that I hoped for, but much higher: 109 for the ticket itself and 60 for the berth (advance bookings could be about twice as cheap). Next, to London! Eurostar is still on a very much reduced schedule, running one train only from Amsterdam through Brussels and Lille to London each day. This means, of course, higher ticket prices (I paid about 100 for the ticket) and longer waiting time in Brussels my sleeper arrives about 10 am, but the Eurostar train is scheduled to depart at 3 pm.

Train route from Brussels to London

The train makes a stop in Lille, which I initially suspected to be risky as at the time when I booked my tickets, as at the time France was on the amber plus list for the UK, requiring a quarantine upon arrival. However, Eurostar announced that they will assign travellers from Lille to a different carriage to avoid other passengers having to go to quarantine, but recently France was taken off the amber plus list. The train fare system in the UK is something I don t quite understand, as sometimes split tickets are cheaper, sometimes they re expensive, sometimes prices for the same service at different times can be vastly different, off-peak tickets don t say what exactly off-peak means (very few people in the UK are asked were able to tell me when exactly off-peak hours are). Curiously, transfers between train stations using London Underground services can be included into railway tickets, but some last mile connection like Exeter to Honiton cannot (but this used to be possible). Both GWR.com and TrainLine refused to sell me a single ticket from London to Honiton through Exeter, insisting I split the ticket at Exeter St Davids or take the slower South Western train to Honiton via Salisbury and Yeovil. I ended up buying a 57 ticket from Paddington to Exeter St Davids with the first segment being the London Underground from St Pancras, and a separate 7.70 ticket to Honiton.

Change of trains in London

Change of trains in Exeter

Date	Station	Arrival	Departure	Train
12.8	Bratislava-Petr alka		18:15	REX 7756
	Wien Hbf	19:15	19:53	NJ 50490
13.8	Bruxelles-Midi	9:55	15:06	EST 9145
	London St Pancras	16:03	16:34	TfL
	London Paddington	16:49	17:04	GWR 59231
	Exeter St Davids	19:19	19:25	SWR 52706
	Honiton	19:54

Unfortunately, due to the price of the tickets, I m taking a 15 Ryanair flight back Update after the journey Since I flew to Charleroi instead of comfortably sleeping in a night train, I had to put up with inconveniences of airports, including cumbersome connections to the nearby cities. The only reasonable way of getting from Charleroi to Brussels is an overcrowded bus which takes almost an hour to arrive. I used to take this bus when I tried to save money on my way to FOSDEM, and I must admit it s not something I missed. Boarding the Eurostar train went fine, my vaccination passport and Covid test wasn t really checked, just glanced at. The waiting room was a bit of a disappointment, with bars closed and vending machines broken. Since it was underground, I couldn t even see the trains until the very last moment when we were finally allowed on the platform. The train itself, while comfortable, disappointed me with the bistro carriage: standing only, instant coffee, poor selection of food and drinks. I m glad I bought some food at Carrefour at the Midi station! When I arrived in Exeter, I soon found out why the system refused to sell me a through ticket: 6 minutes is not enough to change trains at Exeter St Davids! Or, it might have been if I took the right footbridge but I took the one which led into a very talkative (and slow!) lift. I ended up running to the train just as it closed the doors and departed, leaving me tin Exeter for an hour until. I used this chance and walked to Exeter Central, and had a pint in a conveniently located pub around the corner. P.S. The maps in this and other posts were created using uMap; the map data come from OpenStreetMap. The train route visualisation was generated with help of the Raildar.fr OSRM instance.

Two weeks ago I decided to make myself a combined birthday and Christmas present and upgrade my coffee gear. I ve got my first espresso machine back in 2013, it was a cheap Saeco Philips Poemia, which made reasonably drinkable coffee, but not being able to make good coffee made me increasingly unhappy about it. However, since it worked, I wasn t motivated enough to change anything until it stopped working. One day the nut holding the shower screen broke, and I couldn t replace it. Having no coffee machine is arguably worse than having a mediocre one, so I started looking for a new one in the budget range. Having spent about two months reading reviews for all sorts of manual espresso machines, I realised the best thing I can probably do for the money I was willing to spend at the time was to buy a second-hand Gaggia Classic. Which is what I did: I paid 260 to a person who apparently decided they prefer to press a button to get their espresso rather than have to prepare it themselves. My first attempts at making espresso weren t very much successful, as my hand grinder couldn t produce the right grind for espresso (without using pressurised baskets), so I quickly upgraded it to the 50 De Longhi electric grinder, which was much better for espresso.

Gaggia Classic 2015 and De Longhi grinder

This setup has worked for me for nearly 4 years, but over the time the Gaggia started malfunctioning. See, this particular Gaggia Classic is the 2015 model, which resulted in the overhaul of the design after Gaggia was acquired by Philips. They replaced the boiler, changed the exterior design a bit, and importantly for me replaced the fully metal group head with the metal and plastic version typically found in cheap espresso machines like my old Poemia.

The Gaggia Classic 2015 group head

The trouble with this one is that the plastic bit (barely seen on the picture, but it s inserted into the notches on the sides of the group head) is that it gets damaged over the time, especially when the portafilter is inserted very tightly. The more damaged it gets, the tigher it is necessary to insert the portafilter to avoid leakage, the more damaged it gets and so on. At one point, the Gaggia was leaking water every time I was making coffee, affecting the quality of the brew and making a mess in the kitchen. I made a mistake and removed the plastic bit only to realise it cannot be purchased separately and nobody knows how to put it back once it s been removed; I ended up paying more than a hundred euro to replace the group head as a whole. Once I ve got the Gaggia back, I became too conscious of the potential damage I can make by overengaging the portafilter, I decided it s probably the time to get a new coffee machine.

Gaggia Classic 2015 vs 2019

The makers of Gaggia listened to the critics and undid the 2015 changes to the Gaggia Classic design, reverting to the previous one and fixing it they basically merged the fixes many of the owners of the old Gaggia did themselves. The group head is now without any plastic, so I don t have to worry that much about damaging it accidentally. A friend pointed out that my grinder is probably not good enough and recommended a couple of models to me; I checked Kev s Coffee Blog and found a grinder, Sage Dose Control Pro, which was available on sale in my local shop for a reasonable price. I ve also got a portafilter holder to make tamping more comfortable I used to tamp against an edge of the sink:

The final setup:

Gaggia Classic 2019 and Sage BCG600 Dose Control Pro

What I learnt from this is that the grinder does indeed make a huge difference. I am now able to consistently produce brews I would only occasionally get with the old De Longhi grinder. There is one downside to the new grinder. Happy with my new purchase, I went to read this review and thought to myself: lucky me, my grinder is absolutely quiet! And then I realised that the noise in my kitchen is not, in fact, produced by the fridge, but the grinder. Well, a cheap switched plug solved the issue completely (I wish sockets here each had a switch like they usually to in the UK!)

I have been using the awesome window manager for 10 years. It is a tiling window manager, configurable and extendable with the Lua language. Using a general-purpose programming language to configure every aspect is a double-edged sword. Due to laziness and the apparent difficulty of adapting my configuration about 3000 lines to newer releases, I was stuck with the 3.4 version, whose last release is from 2013. It was time for a rewrite. Instead, I have switched to the i3 window manager, lured by the possibility to migrate to Wayland and Sway later with minimal pain. Using an embedded interpreter for configuration is not as important to me as it was in the past: it brings both complexity and brittleness.

Dual screen desktop running i3, Emacs, some terminals, including a Quake console, Firefox, Polybar as the status bar, and Dunst as the notification daemon.

The window manager is only one part of a desktop environment. There are several options for the other components. I am also introducing them in this post.

i3: the window manager i3 aims to be a minimal tiling window manager. Its documentation can be read from top to bottom in less than an hour. i3 organize windows in a tree. Each non-leaf node contains one or several windows and has an orientation and a layout. This information arbitrates the window positions. i3 features three layouts: split, stacking, and tabbed. They are demonstrated in the below screenshot:

Demonstration of the layouts available in i3. The main container is split horizontally. The first child is split vertically. The second one is tabbed. The last one is stacking.

Tree representation of the previous screenshot.

Most of the other tiling window managers, including the awesome window manager, use predefined layouts. They usually feature a large area for the main window and another area divided among the remaining windows. These layouts can be tuned a bit, but you mostly stick to a couple of them. When a new window is added, the behavior is quite predictable. Moreover, you can cycle through the various windows without thinking too much as they are ordered. i3 is more flexible with its ability to build any layout on the fly, it can feel quite overwhelming as you need to visualize the tree in your head. At first, it is not unusual to find yourself with a complex tree with many useless nested containers. Moreover, you have to navigate windows using directions. It takes some time to get used to. I set up a split layout for Emacs and a few terminals, but most of the other workspaces are using a tabbed layout. I don t use the stacking layout. You can find many scripts trying to emulate other tiling window managers but I did try to get my setup pristine of these tentatives and get a chance to familiarize myself. i3 can also save and restore layouts, which is quite a powerful feature. My configuration is quite similar to the default one and has less than 200 lines.

i3 companion: the missing bits i3 philosophy is to keep a minimal core and let the user implements missing features using the IPC protocol:

Do not add further complexity when it can be avoided. We are generally happy with the feature set of i3 and instead focus on fixing bugs and maintaining it for stability. New features will therefore only be considered if the benefit outweighs the additional complexity, and we encourage users to implement features using the IPC whenever possible. Introduction to the i3 window manager

While this is not as powerful as an embedded language, it is enough for many cases. Moreover, as high-level features may be opinionated, delegating them to small, loosely coupled pieces of code keeps them more maintainable. Libraries exist for this purpose in several languages. Users have published many scripts to extend i3: automatic layout and window promotion to mimic the behavior of other tiling window managers, window swallowing to put a new app on top of the terminal launching it, and cycling between windows with Alt+Tab. Instead of maintaining a script for each feature, I have centralized everything into a single Python process, i3-companion using asyncio and the i3ipc-python library. Each feature is self-contained into a function. It implements the following components:

make a workspace exclusive to an application

When a workspace contains Emacs or Firefox, I would like other applications to move to another workspace, except for the terminal which is allowed to intrude into any workspace. The workspace_exclusive() function monitors new windows and moves them if needed to an empty workspace or to one with the same application already running.

implement a Quake console

The quake_console() function implements a drop-down console available from any workspace. It can be toggled with Mod+ . This is implemented as a scratchpad window.

back and forth workspace switching on the same output

With the workspace back_and_forth command, we can ask i3 to switch to the previous workspace. However, this feature is not restricted to the current output. I prefer to have one keybinding to switch to the workspace on the next output and one keybinding to switch to the previous workspace on the same output. This behavior is implemented in the previous_workspace() function by keeping a per-output history of the focused workspaces.

create a new empty workspace or move a window to an empty workspace

To create a new empty workspace or move a window to an empty workspace, you have to locate a free slot and use workspace number 4 or move container to workspace number 4. The new_workspace() function finds a free number and use it as the target workspace.

restart some services on output change

When adding or removing an output, some actions need to be executed: refresh the wallpaper, restart some components unable to adapt their configuration on their own, etc. i3 triggers an event for this purpose. The output_update() function also takes an extra step to coalesce multiple consecutive events and to check if there is a real change with the low-level library xcffib.

I will detail the other features as this post goes on. On the technical side, each function is decorated with the events it should react to:

@on(CommandEvent("previous-workspace"), I3Event.WORKSPACE_FOCUS)
async def previous_workspace(i3, event):
    """Go to previous workspace on the same output."""

The CommandEvent() event class is my way to send a command to the companion, using either i3-msg -t send_tick or binding a key to a nop command. The latter is used to avoid spawning a shell and a i3-msg process just to send a message. The companion listens to binding events and checks if this is a nop command.

bindsym $mod+Tab nop "previous-workspace"

There are other decorators to avoid code duplication: @debounce() to coalesce multiple consecutive calls, @static() to define a static variable, and @retry() to retry a function on failure. The whole script is a bit more than 1000 lines. I think this is worth a read as I am quite happy with the result.

dunst: the notification daemon Unlike the awesome window manager, i3 does not come with a built-in notification system. Dunst is a lightweight notification daemon. I am running a modified version with HiDPI support for X11 and recursive icon lookup. The i3 companion has a helper function, notify(), to send notifications using DBus. container_info() and workspace_info() uses it to display information about the container or the tree for a workspace.

Notification showing i3 s tree for a workspace

polybar: the status bar i3 bundles i3bar, a versatile status bar, but I have opted for Polybar. A wrapper script runs one instance for each monitor. The first module is the built-in support for i3 workspaces. To not have to remember which application is running in a workspace, the i3 companion renames workspaces to include an icon for each application. This is done in the workspace_rename() function. The icons are from the Font Awesome project. I maintain a mapping between applications and icons. This is a bit cumbersome but it looks great.

i3 workspaces in Polybar

For CPU, memory, brightness, battery, disk, and audio volume, I am relying on the built-in modules. Polybar s wrapper script generates the list of filesystems to monitor and they get only displayed when available space is low. The battery widget turns red and blinks slowly when running out of power. Check my Polybar configuration for more details.

Polybar displaying various information: CPU usage, memory usage, screen brightness, battery status, Bluetooth status (with a connected headset), network status (connected to a wireless network and to a VPN), notification status, and speaker volume.

For Bluetooh, network, and notification statuses, I am using Polybar s ipc module: the next version of Polybar can receive an arbitrary text on an IPC socket. The module is defined with a single hook to be executed at the start to restore the latest status.

[module/network]
type = custom/ipc
hook-0 = cat $XDG_RUNTIME_DIR/i3/network.txt 2> /dev/null
initial = 1

It can be updated with polybar-msg action "#network.send.XXXX". In the i3 companion, the @polybar() decorator takes the string returned by a function and pushes the update through the IPC socket. The i3 companion reacts to DBus signals to update the Bluetooth and network icons. The @on() decorator accepts a DBusSignal() object:

@on(
    StartEvent,
    DBusSignal(
        path="/org/bluez",
        interface="org.freedesktop.DBus.Properties",
        member="PropertiesChanged",
        signature="sa sv as",
        onlyif=lambda args: (
            args[0] == "org.bluez.Device1"
            and "Connected" in args[1]
            or args[0] == "org.bluez.Adapter1"
            and "Powered" in args[1]
        ),
    ),
)
@retry(2)
@debounce(0.2)
@polybar("bluetooth")
async def bluetooth_status(i3, event, *args):
    """Update bluetooth status for Polybar."""

The middle of the bar is occupied by the date and a weather forecast. The latest also uses the IPC mechanism, but the source is a Python script triggered by a timer.

Current date and weather forecast for the day in Polybar. The data is retrieved with the OpenWeather API.

I don t use the system tray integrated with Polybar. The embedded icons usually look horrible and they all behave differently. A few years back, Gnome has removed the system tray. Most of the problems are fixed by the DBus-based Status Notifier Item protocol also known as Application Indicators or Ayatana Indicators for GNOME. However, Polybar does not support this protocol. In the i3 companion, The implementation of Bluetooth and network icons, including displaying notifications on change, takes about 200 lines. I got to learn a bit about how DBus works and I get exactly the info I want.

picom: the compositor I like having slightly transparent backgrounds for terminals and to reduce the opacity of unfocused windows. This requires a compositor.¹ picom is a lightweight compositor. It works well for me, but it may need some tweaking depending on your graphic card.² Unlike the awesome window manager, i3 does not handle transparency, so the compositor needs to decide by itself the opacity of each window. Check my configuration for details.

systemd: the service manager I use systemd to start i3 and the various services around it. My xsession script only sets some environment variables and lets systemd handles everything else. Have a look at this article from Micha G ral for the rationale. Notably, each component can be easily restarted and their logs are not mangled inside the ~/.xsession-errors file.³ I am using a two-stage setup: i3.service depends on xsession.target to start services before i3:

[Unit]
Description=X session
BindsTo=graphical-session.target
Wants=autorandr.service
Wants=dunst.socket
Wants=inputplug.service
Wants=picom.service
Wants=pulseaudio.socket
Wants=policykit-agent.service
Wants=redshift.service
Wants=spotify-clean.timer
Wants=ssh-agent.service
Wants=xiccd.service
Wants=xsettingsd.service
Wants=xss-lock.service

Then, i3 executes the second stage by invoking the i3-session.target:

[Unit]
Description=i3 session
BindsTo=graphical-session.target
Wants=wallpaper.service
Wants=wallpaper.timer
Wants=polybar-weather.service
Wants=polybar-weather.timer
Wants=polybar.service
Wants=i3-companion.service
Wants=misc-x.service

Have a look on my configuration files for more details.

rofi: the application launcher Rofi is an application launcher. Its appearance can be customized through a CSS-like language and it comes with several themes. Have a look at my configuration for mine.

Rofi as an application launcher

It can also act as a generic menu application. I have a script to control a media player and another one to select the wifi network. It is quite a flexible application.

Rofi to select a wireless network

xss-lock and i3lock: the screen locker i3lock is a simple screen locker. xss-lock invokes it reliably on inactivity or before a system suspend. For inactivity, it uses the XScreenSaver events. The delay is configured using the xset s command. The locker can be invoked immediately with xset s activate. X11 applications know how to prevent the screen saver from running. I have also developed a small dimmer application that is executed 20 seconds before the locker to give me a chance to move the mouse if I am not away.⁴ Have a look at my configuration script.

Demonstration of xss-lock, xss-dimmer and i3lock with a 4 speedup.

The remaining components

• autorandr is a tool to detect the connected display, match them against a set of profiles, and configure them with xrandr.
• inputplug executes a script for each new mouse and keyboard plugged. This is quite useful to load the appropriate the keyboard map. See my configuration.
• xsettingsd provides settings to X11 applications, not unlike xrdb but it notifies applications for changes. The main use is to configure the Gtk and DPI settings. See my article on HiDPI support on Linux with X11.
• Redshift adjusts the color temperature of the screen according to the time of day.
• maim is a utility to take screenshots. I use Prt Scn to trigger a screenshot of a window or a specific area and Mod+Prt Scn to capture the whole desktop to a file. Check the helper script for details.
• I have a collection of wallpapers I rotate every hour. A script selects them using advanced machine learning algorithms and stitches them together on multi-screen setups. The selected wallpaper is reused by i3lock.

---

1. Apart from the eye candy, a compositor also helps to get tear-free video playbacks.
2. My configuration works with both Haswell (2014) and Whiskey Lake (2018) Intel GPUs. It also works with AMD GPU based on the Polaris chipset (2017).
3. You cannot manage two different displays this way e.g. :0 and :1. In the first implementation, I did try to parametrize each service with the associated display, but this is useless: there is only one DBus user session and many services rely on it. For example, you cannot run two notification daemons.
4. I have only discovered later that XSecureLock ships such a dimmer with a similar implementation. But mine has a cool countdown!

Following dkg s example, I decided to finally transition to my new ed25519/cv25519 key. Unlike Daniel, I m not yet trying to split identities, but I m using this chance to drop old identities I no longer use. My new key only has my main email address and the Debian one, and only those versions of my name I still want around. My old PGP key (at the moment in the Debian keyring) is: The is the key I ve been using in Debian from the very beginning, and its copies at the SKS keyserver network still have my first DD signature from angdraug: My new PGP key is: If you signed my old key and are reading this, please consider signing my new key; if you feel you need to re-confirm this, feel free to contact me; otherwise, a copy of this statement signed by both the old and new keys is available here. I have uploaded this new key to keys.openpgp.org, and also published it through WKD and the SKS network. Both keys can also be downloaded from my website.

I ve just made my blog available on the Fediverse, at least partially. Yesterday while browsing Hacker News, I saw Carl Schwan s post Adding comments to your static blog with Mastodon^(m) about him replacing Disqus with replies posted at Mastodon. Just on Monday I was thinking, why can t blogs participate in Fediverse? I tried to use WriteFreely as a replacement for Pelican, only to find it very limited, so I thought I might write a gateway to expose the Atom feed using ActivityPub. Turns out, someone already did that: Bridgy, a service connecting websites to Twitter, Mastodon and other social media, also has a Fediverse counterpart, Fed.brid.gy just what I was looking for! I won t go deeply into the details, but just outline issues I had to deal with:

• Bridgy relies on microformats. While I had some microformats and Schema.org microdata already at both blog and the homepage, they were not sufficiently good for Bridgy to use.
• Webmention: I had to set up https://webmention.io to act as Webmention host for me.
• I ran into an issue with Mastodon being more picky about signatures which the author Ryan Barrett promptly fixed.

The end result is not fully working yet, since posts don t appear yet, but I can be found and followed as @shadura.me@shadura.me. As a bonus I enabled IndieAuth at my website, so I can log into compatible services with just the URL of my website.

Recently, I needed to package a Rust crate libslirp for a Apertis, a Debian derivative. libslirp is used by the newly release UML backend of debos, our Debian image build tool. Unfortunately, this crate hasn t yet been properly packaged for Debian proper, so I could not simply pull the packaging from Debian. Even worse, its build dependencies haven t all been packaged yet. Most importantly, I have only uploaded zbus to Debian today, and at that time none of its dependencies were in Debian either. Another issue with this were that each crate is packaged for Debian as a separate package, making the process a bit more tricky since I d need to import all of the crates into Apertis separately. Doing that takes time and is further complicated by the CI loop we re using which requires the full build process to complete for a package before a pipeline a dependent package can run. Having all that considered, I took a shortcut: I vendored all the build dependencies with the package itself, and here s how. I started with debcargo-conf, where the not-yet-complete packaging lives. With debcargo, I generated the source package as if I were to upload to Debian. Since I ll be vendoring the dependencies, I have removed most of the Rust dependencies and replaced them with those extra dependencies needed by those crates. So, I replaced this: By this: I wanted to keep the delta to the future Debian package at a bare minimum, so I kept the original dh-cargo build process, only making sure the vendored dependencies are found in the right place. The cleanest approach in my view was to use the fact that the 3.0 (quilt) source format allows multiple original tarballs: the main tarball would be the same orig tarball as in Debian, and an extra tarball would contain the vendored code. When we sync with Debian, the extra tarball would be dropped, just as the adjustments to the debian/rules. To generate the vendor tarball, I added this to the rules file: This target, being run manually and not as part of the build process, download the latest dependencies satisfying the requirements in Cargo.toml and rolls them into a vendor tarball. Now, to make dh-cargo use the vendored code, we need to link it into the right place. dh-cargo creates a Cargo registry tree in a subdirectly under debian/ where it symlinks crates from the Rust development packages. This extra code makes sure the vendored dependencies are available there too: An important thing here is that if the build happens on a non-clean system, dh-cargo may have symlinked a system crate already installed so we need to remove that symlink and replace it by ours. We build packages in clean chroots, so this is not that important, otherwise for reproducibility reasons it would be better to create the registry directory from scratch. The final package can be found at the Apertis GitLab.

As a response to Antonio Terceiro s blog post, I m publishing some FFmpeg commands I ve been using recently. Embedding subtitles Sometimes you have a video with subtitles in multiple languages and you don t want to clutter the directory with a lot of similarly-named files or maybe you want to be able to easily transfer the video and subtitles at once. In this case, it may be useful to embed to subtitles directly into the video container file. This commands recodes the subtitle file into a format appropriate for the MP4 container and embeds it with a metadata element telling the video player what language it is in. You can add multiple subtitles at once, or you can also transcode the audio to AAC while doing so (I found that a lot of Android devices can t play Ogg Vorbis streams): Hard subtitles Sometimes you need to play the video with subtitles on devices not supporting them. In that case, it may be useful to hardcode the subtitles directly into the video stream: Unfortunately, if you also want to apply more transformations to the video, it starts getting tricky, the -vf option is no longer enough: This command adds an overlay to the video stream (in my case I overlaid a full frame over the original video offering some explanations), increases the volume ten times and adds hard subtitles. P.S. You can see the practical application of the above in this video with a head of one of the electoral commissions in Belarus forcing the members of the staff to manipulate the voting results. I transcribed the video in both Russian and English and encoded the English subtitles into the video.

Earlier this month I had the pleasure of attending the Web Engines Hackfest, hosted by Igalia at their offices in A Coru a, and also sponsored by my employer, Collabora, Google and Mozilla. It has grown a lot and we had many new people this year. Fun fact: I am one of the 3 or 4 people who have attended all of the editions of the hackfest since its inception in 2009, when it was called WebKitGTK+ hackfest \o/ It was a great get together where I met many friends and made some new ones. Had plenty of discussions, mainly with Antonio Gomes and Google s Robert Kroeger, about the way forward for Chromium on Wayland. We had the opportunity of explaining how we at Collabora cooperated with igalians to implemented and optimise a Wayland nested compositor for WebKit2 to share buffers between processes in an efficient way even on broken drivers. Most of the discussions and some of the work that led to this was done in previous hackfests, by the way! The idea seems to have been mostly welcomed, the only concern being that Wayland s interfaces would need to be tested for security (fuzzed). So we may end up going that same route with Chromium for allowing process separation between the UI and GPU (being renamed Viz, currently) processes. On another note, and going back to the title of the post, at Collabora we have recently adopted Mattermost to replace our internal IRC server. Many Collaborans have decided to use Mattermost through an Epiphany Web Application or through a simple Python application that just shows a GTK+ window wrapping a WebKitGTK+ WebView. Some people noticed that when the connection was lost Mattermost would take a very long time to notice and reconnect its web sockets were taking a long, long time to timeout, according to our colleague Andrew Shadura. I did some quick searching on the codebase and noticed WebCore has a NetworkStateNotifier interface that it uses to get notified when connection changes. That was not implemented for WebKitGTK+, so it was likely what caused stuff to linger when a connection hiccup happened. Given we have GNetworkMonitor, implementation of the missing interfaces required only 3 lines of actual code (plus the necessary boilerplate)! I was surprised to still find such as low hanging fruit in WebKitGTK+, so I decided to look for more. Turns out WebCore also has a notifier for low power situations, which was implemented only by the iOS port, and causes the engine to throttle some timers and avoid some expensive checks it would do in normal situations. This required a few more lines to implement using upower-glib, but not that many either! That was the fun I had during the hackfest in terms of coding. Mostly I had fun just lurking in break out sessions discussing the past, present and future of tech such as WebRTC, Servo, Rust, WebKit, Chromium, WebVR, and more. I also beat a few challengers in Street Fighter 2, as usual. I d like to say thanks to Collabora, Igalia, Google, and Mozilla for sponsoring and attending the hackfest. Thanks to Igalia for hosting and to Collabora for sponsoring my attendance along with two other Collaborans. It was a great hackfest and I m looking forward to the next one! See you in 2018 =)

In December last year, OpenEmbebbed introduced automatic debug packages. Prior to that, you d need to manually construct FILES_$ PN -dbg variable in your recipe. If you need to retain manual control over precisely what does into debug packages, set an undocumented NOAUTOPACKAGEDEBUG variable to 1, the same way Qt recipe does:

NOAUTOPACKAGEDEBUG = "1"
FILES_$ PN -dev = "$ includedir /$ QT_DIR_NAME /Qt/*"
FILES_$ PN -dbg = "/usr/src/debug/"
FILES_$ QT_BASE_NAME -demos-doc = "$ docdir /$ QT_DIR_NAME /qch/qt.qch"

P.S. Knowing this would have saved me and my colleagues days of work.

Yesterday I was fixing an issue with one of the servers behind kallithea-scm.org: the hook intended to propagage pushes from Our Own Kallithea to Bitbucket stopped working. Until yesterday, that server was using Debian s flavour of System V init and djb s d montools to keep things running. To make the hook asynchronous, I wrote a service to be managed to d montools, so that concurrency issued would be solved by it. However, I didn t implement any timeouts, so when last week wget froze while pulling Weblate s hook, there was nothing to interrupt it, so the hook stopped working since d montools thought it s already running and wouldn t re-trigger it. Killing wget helped, but I decided I need to do something with it to prevent the situation from happening in the future. I ve been using systemd at work for the last year, so I am now confident I m happier with systemd than with d montools, so I decided to switch the server to systemd. Not surprisingly, I prepared unit files in about 5 minutes without having to look into the manuals again, while with d montools I had to check things every time I needed to change something. The tricky thing was the switch itself. It is a virtual server, presumably running in Xen, and I don t have access to the console, so if I bork break something, I need to summon Bradley Kuhn or someone from Conservancy, who s kindly donated the server to the project. In any case, I decided to attempt to upgrade without a reboot, so that I have more options to roll back my changes in the case things go wrong. After studying the manpages of both systemd s init and sysvinit s init, I realised I can install systemd as /sbin/init and ask already running System V init to re-exec. However, systemd s init can t talk to System V init, so before installing systemd I made a backup on it. It s also important to stop all running services (except probably ssh) to make sure systemd doesn t start second instances of each. And then: /tmp/init u and we re running systemd! A couple of additional checks, and it s safe to reboot. Only when I did all that I realised that in the case of systemd not working I d probably not be able to undo my changes if my connection interrupted. So, even though at the end it worked, probably it s not a good idea to perform such manipulations when you don t have an alternative way to connect to the server :)

What happened in the reproducible builds effort between February 28th and March 5th:

Toolchain fixes

• Antonio Terceiro uploaded gem2deb/0.27 that forces generated gemspecs to use the date from debian/changelog.
• Antonio Terceiro uploaded gem2deb/0.28 that forces generated gemspecs to have their contains file lists sorted.
• Robert Luberda uploaded ispell/3.4.00-5 which make builds of hashes reproducible.
• C dric Boutillier uploaded ruby-ronn/0.7.3-4 which will make the output locale agnostic. Original patch by Chris Lamb.
• Markus Koschany uploaded spring/101.0+dfsg-1. Fixed by Alexandre Detiste.

Ximin Luo resubmitted the patch adding the --clamp-mtime option to Tar on Savannah's bug tracker. Lunar rebased our experimental dpkg on top of the current master branch. Changes in the test infrastructure are required before uploading a new version to our experimental repository. Reiner Herrmann rebased our custom texlive-bin against the latest uploaded version.

Packages fixed The following 77 packages have become reproducible due to changes in their build dependencies: asciidoctor, atig, fuel-astute, jekyll, libphone-ui-shr, linkchecker, maven-plugin-testing, node-iscroll, origami-pdf, plexus-digest, pry, python-avro, python-odf, rails, ruby-actionpack-xml-parser, ruby-active-model-serializers, ruby-activerecord-session-store, ruby-api-pagination, ruby-babosa, ruby-carrierwave, ruby-classifier-reborn, ruby-compass, ruby-concurrent, ruby-configurate, ruby-crack, ruby-css-parser, ruby-cucumber-rails, ruby-delorean, ruby-encryptor, ruby-fakeweb, ruby-flexmock, ruby-fog-vsphere, ruby-gemojione, ruby-git, ruby-grack, ruby-htmlentities, ruby-jekyll-feed, ruby-json-schema, ruby-listen, ruby-markerb, ruby-mathml, ruby-mini-magick, ruby-net-telnet, ruby-omniauth-azure-oauth2, ruby-omniauth-saml, ruby-org, ruby-origin, ruby-prawn, ruby-pygments.rb, ruby-raemon, ruby-rails-deprecated-sanitizer, ruby-raindrops, ruby-rbpdf, ruby-rbvmomi, ruby-recaptcha, ruby-ref, ruby-responders, ruby-rjb, ruby-rspec-rails, ruby-rspec, ruby-rufus-scheduler, ruby-sass-rails, ruby-sass, ruby-sentry-raven, ruby-sequel-pg, ruby-sequel, ruby-settingslogic, ruby-shoulda-matchers, ruby-slack-notifier, ruby-symboltable, ruby-timers, ruby-zip, ticgit, tmuxinator, vagrant, wagon, yard. The following packages became reproducible after getting fixed:

• air-quality-sensor/0.1.4-1 uploaded by Benedikt Wildenhain, fixed upstream, original patch by Chris Lamb.
• device3dfx/2013.08.08-4 by Guillem Jover.
• fldigi/3.23.08-1 by Kamal Mostafa.
• fltk1.1/1.1.10-22 by Aaron M. Ucko.
• freeimage/3.17.0+ds1-2 by Ghislain Antony Vaillant.
• gimagereader/3.1.2+git368fa8f-2 by Philip Rinn.
• ginkgocadx/3.7.5-1 by Gert Wollny, fixed upstream.
• jadetex/3.13-17 by Norbert Preining.
• opensips/2.1.2-1 by Razvan Crainea.
• ruby-sqlite3/1.3.11-2 uploaded by C dric Boutillier, original patch by Lunar.
• runawk/1.6.0-2 uploaded by Andrew Shadura, patch by Reiner Herrmann.
• systraq/20160303-1 by Joost van Baal-Ili .

Some uploads fixed some reproducibility issues, but not all of them:

• auto-multiple-choice/1.2.1-4 by Georges Khaznadar.
• avfs/1.0.3-1 uploaded by Michael Meskes, original patch by Chris Lamb.
• console-setup/1.138 uploaded by Anton Zinoviev, original patch by Reiner Herrmann.
• gromacs/5.1.2-1 by Nicholas Breen.
• mrrescue/1.02c-2 by Alexandre Detiste.
• usb-modeswitch-data/20160112-2 by Didier Raboud.

Patches submitted which have not made their way to the archive yet:

• #816209 on elog by Reiner Herrmann: use printf instead of echo which is shell-independent.
• #816214 on python-pip by Reiner Herrmann: removes timestamp from generated Python scripts.
• #816230 on rows by Reiner Herrmann: tell grep to always treat the input as text.
• #816232 on eficas by Reiner Herrmann: use printf instead of echo which is shell-independent.

Florent Daigniere and bancfc reported that linux-grsec was currently built with GRKERNSEC_RANDSTRUCT which will prevent reproducible builds with the current packaging.

tests.reproducible-builds.org pbuilder has been updated to the last version to be able to support Build-Depends-Arch and Build-Conflicts-Arch. (Mattia Rizzolo, h01ger) New package sets have been added for Subgraph OS, which is based on Debian Stretch: packages and build dependencies. (h01ger) Two new armhf build nodes have been added (thanks Vagrant Cascadian) and integrated in our Jenkins setup with 8 new armhf builder jobs. (h01ger)

strip-nondeterminism development strip-nondeterminism version 0.016-1 was released on Sunday 28th. It will now normalize the POT-Creation-Date field in GNU Gettext .mo files. (Reiner Herrmann) Several improvements to the packages metadata have also been made. (h01ger, Ben Finney)

Package reviews 185 reviews have been removed, 91 added and 33 updated in the previous week. New issue: fileorder_in_gemspec_files_list. 43 FTBFS bugs were reported by Chris Lamb, Martin Michlmayr, and gregor herrmann.

Misc. After merging the patch from Dhiru Kholia adding support for SOURCE_DATE_EPOCH in rpm, Florian Festi opened a discussion on the rpm-ecosystem mailing list about reproducible builds. On March 4th, Lunar gave an overview of the general reproducible builds effort at the Internet Freedom Festival in Valencia.

If you bought an North India travel guide by Vanessa Betts and Victoria McCulloch, and tried to figure out where is Phulud and how to get there from Deogarh (and how to get to Deogarh itself from Udaipur), don t waste your time googling, as it s not Phulud, but Phulad. It does seem that the narrow gauge journey from Deogarh to Phulad is indeed beautiful: Meanwhile, I have also found this very interesting post by Mary Anne Erickson: Impressions of India: Udaipur to Deogarh. I m not yet sure we re going to follow that route, but it seems promising. P.S. Despite what the guide said about the airport in Jaisalmer, which is due to open in 2013, according to the reports, it is still not open, so we have to skip that city. Oh well. EDIT: The guide actually also says, on page 10: Fly from Jaisalmer back to Delhi to connect with your flight home. Fact checking? No, who needs that? :)

I haven t yet blogged about this (as normally I don t blog often), but I joined Collabora in June last year. Since then, I had an opportunity to work with OpenEmbedded again, write a kernel patch, learn lots of things about systemd (in particular, how to stop worrying about it taking over the world and so on), and do lots of other things. As one would expect when working for a free software consultancy, our customers do understand the value of the community and contributing back to it, and so does the customer for the project I m working on. In fact, our customer insists we keep the number of locally applied patches to, for example, Linux kernel, to minimum, submitting as much as possible upstream. However, apart from the upstreaming work which may be done for the customer, Collabora encourages us, the engineers, to spend up to two hours weekly for upstreaming on top of what customers need, and up to five days yearly as paid Community days. These community days may be spent working on the code or doing volunteering at free software events or even speaking at conferences. Even though on this project I have already been paid for contributing to the free software project which I maintained in my free time previously (ifupdown), paid community time is a great opportunity to contribute to the projects I m interested in, and if the projects I m interested in coincide with the projects I m working with, I effectively can spend even more time on them. A bit unfortunately for me, I haven t spent enough time last year to plan my community days, so I used most of them in the last weeks of the calendar year, and I used them (and some of my upstreaming hours) on something that benefitted both free software community and Collabora. I m talking about SparkleShare, a cross-platform Git-based file synchronisation solution written in C#. SparkleShare provides an easy to use interface for Git, or, actually, it makes it possible to not use any Git interface at all, as it monitors the working directory using inotify and commits stuff right after it changes. It automatically handles conflicts even for binary files, even though I have to admit its handling could still be improved. At Collabora, we use SparkleShare to store all sorts of internal documents, and it s being used by users not familiar with command line interfaces too. Unfortunately, the version we recently had in Debian had a couple of very annoying bugs, making it a great pain to use it: it would not notice edits in local files, or not notice new commits being pushed to the server, and that led to individual users edits being lost sometimes. Not cool, especially when the document has to be sent to the customer in a couple of minutes. The new versions, 1.4 (and recently released 1.5) was reported as being much better and also fixing some crashes, but it also used GTK+ 3 and some libraries not yet packaged for Debian. Thanh Tung Nguyen packaged these packages (and a newer SparkleShare) for Ubuntu and published them in his PPA, but they required some work to be fit for Debian. I have never touched Mono packages before in my life, so I had to learn a lot. Some time was spent talking to upstream about fixing their copyright statements (they had none in the code, and only one author was mentioned in configure.ac, and nowhere else in the source), a bit more time went into adjusting and updating the patches to the current source code version. Then, of course, waiting the packages to go through NEW. Fixing parallel build issues, waiting for buildds to all build dependencies for at least one architecture But then, finally, on 19^th of January I had the updated SparkleShare in Debian. As you may have already guessed, this blog post has been sponsored by Collabora, the first of my employers to encourage require me to work on free software in my paid time :)

Holger Levsen writes about the public transport map of Managua, Nicaragua, which is, according to him, the first detailed map of Managua s bus network:

If you haven t been to Managua, you might not be able to immediatly appreciate the usefulness of this. Up until now, there has been no map nor timetable for the bus system, which as you can see now easily and from far away, is actually quite big and is used by 80% of the population in a city, where the streets still have no names.

Having had a look at the map they produced, I have to admit I quite liked it: MapaNica, the community behind said map, are raising funds to make lives of locals easier by publishing a printed version of the map and distributing it. They have already raised more than $3300 of their $7500 goal. Every further donation will help them print more maps. Please go to support.mapanica.net and support their initiative!

What happened in the reproducible builds effort between December 20th to December 26th: Toolchain fixes Mattia Rizzolo rebased our experimental versions of debhelper (twice!) and dpkg on top of the latest releases. Reiner Herrmann submited a patch for mozilla-devscripts to sort the file list in generated preferences.js files. To be able to lift the restriction that packages must be built in the same path, translation support for the __FILE__ C pre-processor macro would also be required. Joerg Sonnenberger submitted a patch back in 2010 that would still be useful today. Chris Lamb started work on providing a deterministic mode for debootstrap. Packages fixed The following packages have become reproducible due to changes in their build dependencies: bouncycastle, cairo-dock-plug-ins, darktable, gshare, libgpod, pafy, ruby-redis-namespace, ruby-rouge, sparkleshare. The following packages became reproducible after getting fixed:

• a7xpg/0.11.dfsg1-9 uploaded by Markus Koschany, original patch by Reiner Herrmann.
• at/3.1.18-1 uploaded by Laurent Bigonville, original patch by Reiner Herrmann, merged by Jose M Calhariz.
• bibtool/2.61+ds-2 by Jerome Benoit.
• bup/0.27-2 uploaded by Robert Edmonds, original patch by Chris Lamb.
• deja-dup/34.1-1 uploaded by Laurent Bigonville, original patch by Reiner Herrmann.
• gauche-gl/0.6-1 by NIIBE Yutaka.
• ifupdown/0.8 uploaded by Guus Sliepen, original patch by Lunar.
• jing-trang/20131210+dfsg+1-4 by Samuel Thibault.
• libp11/0.3.0-2 by Eric Dorland.
• pdns/4.0.0~alpha1-1 by Christian Hofstaedtler.
• pdns-recursor/4.0.0~alpha1-1 by Christian Hofstaedtler.
• qupzilla/1.8.9~dfsg1-1 uploaded by Georges Khaznadar, fixed upstream.
• ros-genpy/0.5.7-4 uploaded by Jochen Sprickerhof, original patch by Chris Lamb.
• signify/1.14-3 by Mattia Rizzolo, obsoleting patches submitted by Chris Lamb and akira.
• sleepyhead/0.9.8-2 by Sergio Durigan Junior.
• texi2html/1.82+dfsg1-5 by Mattia Rizzolo, previous patch by Juan Picca.
• titanion/0.3.dfsg1-6 by Markus Koschany, original patch by Reiner Herrmann.
• tj3/3.5.0-3 uploaded by Vincent Bernat, original patch by Vincent Bernat.
• vcsh/1.20151229-1 by Richard Hartmann.
• waitress/0.8.10-1 uploaded by Andrew Shadura, original patch by Juan Picca.
• xtel/3.3.0-19 by Samuel Thibault.

Some uploads fixed some reproducibility issues, but not all of them:

• kmod/22-1 uploaded by Marco d'Itri, original patch by Lunar.
• libgcrypt20/1.6.4-4 by Andreas Metzler.
• loadlin/1.6f-4 uploaded by Samuel Thibault, original patch by Chris Lamb.
• pathological/1.1.3-13 uploaded by Markus Koschany, original patch by Chris Lamb.
• yacas/1.3.6-1) uploaded by Muammar El Khatib, original patch by Reiner Herrmann.

Patches submitted which have not made their way to the archive yet:

• #808459 on pywavelets by Chris Lamb: add support for SOURCE_DATE_EPOCH in the documentation generator.
• #808652 on nexuiz-data by Reiner Herrmann: sorts with the locale set to C.
• #808667 on libmouse-perl by Reiner Herrmann: sorts the list of filenames to be embedded.
• #808679 on libcorelinux by Reiner Herrmann: sort the list of files in the generated Makefile.
• #808711 on ca-certificates by Reiner Herrmann: sort the list of certificates before it is embedded.

reproducible.debian.net Statistics for package sets are now visible for the armhf architecture. (h01ger) The second build now has a longer timeout (18 hours) than the first build (12 hours). This should prevent wasting resources when a machine is loaded. (h01ger) Builds of Arch Linux packages are now done using a tmpfs. (h01ger) 200 GiB have been added to jenkins.debian.net (thanks to ProfitBricks!) to make room for new jobs. The current count is at 962 and growing! diffoscope development Aside from some minor bugs that have been fixed, a one-line change made huge memory (and time) savings as the output of transformation tool is now streamed line by line instead of loaded entirely in memory at once. disorderfs development Andrew Ayer released disorderfs version 0.4.2-1 on December 22th. It fixes a memory corruption error when processing command line arguments that could cause command line options to be ignored. Documentation update Many small improvements for the documentation on reproducible-builds.org sent by Georg Koppen were merged. Package reviews 666 (!) reviews have been removed, 189 added and 162 updated in the previous week. 151 new fail to build from source reports have been made by Chris West, Chris Lamb, Mattia Rizzolo, and Niko Tyni. New issues identified: unsorted_filelist_in_xul_ext_preferences, nondeterminstic_output_generated_by_moarvm. Misc. Steven Chamberlain drew our attention to one analysis of the Juniper ScreenOS Authentication Backdoor: Whilst this may have been added in source code, it was well-disguised in the disassembly and just 7 instructions long. I thought this was a good example of the current state-of-the-art, and why we'd like our binaries and eventually, installer and VM images reproducible IMHO. Joanna Rutkowska has mentioned possible ways for Qubes to become reproducible on their development mailing-list.

The first reproducible world summit was held in Athens, Greece, from December 1st-3rd with the support of the Linux Foundation, the Open Tech Fund, and Google. Faidon Liambotis has been an amazing help to sort out all local details. People at ImpactHub Athens have been perfect hosts. Nearly 40 participants from 14 different free software project had very busy days sharing knowledge, building understanding, and producing actual patches. Anyone interested in cross project discussions should join the rb-general mailing-list. What follows focuses mostly on what happened for Debian this previous week. A more detailed report about the summit will follow soon. You can also read the ones from Joachim Breitner from Debian, Clemens Lang from MacPorts, Georg Koppen from Tor, Dhiru Kholia from Fedora, and Ludovic Court s wrote one for Guix and for the GNU project. Infrastructure Several discussions at the meeting helped refine a shared understanding of what kind of information should be recorded on a build, and how they could be used. Daniel Kahn Gillmor sent a detailed update on how .buildinfo files should become part of the Debian archive. Some key changes compared to what we had in mind at DebConf15:

• Two .buildinfo with different environment information can attest to the same exact binary artifact.
• Multiple .buildinfo files can coexist for the same .deb as long as the listed checksums match the source and binary package in the archive.
• .buildinfo can be signed in-line to certify where a build comes from.

Hopefully, ftpmasters will be able to comment on the updated proposal soon. Packages fixed The following packages have become reproducible due to changes in their build dependencies: fades, triplane, caml-crush, globus-authz. The following packages became reproducible after getting fixed:

• binutils/2.25.90.20151125-2 uploaded by Matthias Klose, original patch by Reiner Herrmann.
• chocolate-doom/2.2.1-2 by Fabian Greffrath.
• csound/1:6.05~dfsg1-7 by Felipe Sateler.
• dispcalgui/3.0.5.0-1 uploaded by Christian Marillat, original patch by Reiner Herrmann.
• drmips/2.0.1-1 by Bruno Nova.
• ghc/7.10.1-5 by Joachim Breitner.
• gitolite3/3.6.3-3 by David Bremner.
• libdigidoc/3.10.1.1208+ds1-1 uploaded by Andrew Shadura, original patch by Reiner Herrmann.
• liberasurecode/1.1.0-3 uploaded by Thomas Goirand, original patch by Chris Lamb.
• libjs-jcrop/0.9.13+dfsg-1 uploaded by David Pr vot, original patch by Chris Lamb.
• libnet-interface-perl/1.012-3 uploaded by gregor herrmann, original patch by Reiner Herrmann.
• libosmocore/0.9.0-1 uploaded by Ruben Undheim, original patch by Reiner Herrmann.
• libperl-apireference-perl/0.21-2 fixed by Niko Tyni (#807111).
• netrik/1.16.1-2 by Axel Beckert.
• openssl/1.0.2e-1 by Kurt Roeckx.
• snp-sites/2.0.2-2 uploaded by Sascha Steinbiss, original patch by Reiner Herrmann.
• xfonts-shinonome/1:0.9.11-1 by Hideki Yamane, original patch by Chris Lamb.

Some uploads fixed some reproducibility issues, but not all of them:

• raster3d/3.0-3-2 uploaded by Andreas Tille, original patch by Lunar.

Patches submitted which have not made their way to the archive yet:

• #806580 on metview by Reiner Herrmann: remove timestamps from metview script.
• #806974 on xpra by Reiner Herrmann: interpret the changelog date as UTC.
• #807051 on why by Valentin Lorentz: removes extra timestamps from the build system.

akira sent proposals on how to make bash reproducible. Alexander Couzens submitted a patch upstream to add support for SOURCE_DATE_EPOCH in grub image generator (#787795). reproducible.debian.net An issue with some armhf build nodes was tracked down to a bad interaction between uname26 personality and new glibc (Vagrant Cascadian). A Debian package was created for koji, the RPM building and tracking system used by Fedora amongst others. It is currently waiting for review in the NEW queue. (Ximin Luo, Marek Marczykowski-G recki) diffoscope development diffoscope now has a dedicated mailing list to better accommodate its growing user and developer base. Going through diffoscope's guts together enabled several new contributors. Baptiste Daroussin, Ed Maste, Clemens Lang, Mike McQuaid, Joachim Breitner all contributed their first patches to improve portability or add new features. Regular contributors Chris Lamb, Reiner Herrmann, and Levente Polyak also submitted improvements. The next release should support more operating systems, filesystem image comparison via libguestfs, HTML reports with on-demand loading, and parallel processing for the most noticeable improvements. Package reviews 27 reviews have been removed, 17 added and 14 updated in the previous week. Chris Lamb and Val Lorentz filed 4 new FTBFS reports. Misc. Baptiste Daroussin has started to implement support for SOURCE_DATE_EPOCH in FreeBSD in libpkg and the ports tree. Thanks Joachim Breitner and h01ger for the pictures.

The Software Freedom Conservancy are desperately looking for financial support after one of their corporate supporters have stopped their sponsorship. This week, there s an anonymous pledge to match donations from new supporters. Becoming an SFC supporter will help them fight for our software freedom. I have signed up for a monthly donation, and I suggest you do so too here.

A good amount of the Debian reproducible builds team had the chance to enjoy face-to-face interactions during DebConf15.

Names in red and blue were all present at DebConf15

Hugging people with whom one has been working tirelessly for months gives a lot of warm-fuzzy feelings. Several recorded and hallway discussions paved the way to solve the remaining issues to get reproducible builds part of Debian proper. Both talks from the Debian Project Leader and the release team mentioned the effort as important for the future of Debian. A forty-five minutes talk presented the state of the reproducible builds effort. It was then followed by an hour long roundtable to discuss current blockers regarding dpkg, .buildinfo and their integration in the archive. Toolchain fixes

• Kenneth J. Pronovici uploaded epydoc/3.0.1+dfsg-12 which makes class and modules ordering predictable (#795835) and fixes __repr__ so memory addresses don't appear in docs (#795826). Patches by Val Lorentz.
• Sergei Golovan uploaded erlang/1:18.0-dfsg-2 which adds support for SOURCE_DATE_EPOCH to erlc. Patch by Chris West (Faux) and Chris Lamb.
• Dmitry Shachnev uploaded sphinx/1.3.1-5 which make grammar, inventory, and JavaScript locales generation deterministic. Original patch by Val Lorentz.
• St phane Glondu uploaded ocaml/4.02.3-2 to experimental, making startup files and native packed libraries deterministic. The patch adds deterministic .file to the assembler output.
• Enrico Tassi uploaded lua-ldoc/1.4.3-3 which now pass the -d option to txt2man and add the --date option to override the current date.

Reiner Herrmann submitted a patch to make rdfind sort the processed files before doing any operation. Chris Lamb proposed a new patch for wheel implementing support for SOURCE_DATE_EPOCH instead of the custom WHEEL_FORCE_TIMESTAMP. akira sent one making man2html SOURCE_DATE_EPOCH aware.

• #796330 on d-shlibs by Reiner Herrmann: sort with LC_ALL set to C.

St phane Glondu reported that dpkg-source would not respect tarball permissions when unpacking under a umask of 002. After hours of iterative testing during the DebConf workshop, Sandro Knau created a test case showing how pdflatex output can be non-deterministic with some PNG files. Packages fixed The following 65 packages became reproducible due to changes in their build dependencies: alacarte, arbtt, bullet, ccfits, commons-daemon, crack-attack, d-conf, ejabberd-contrib, erlang-bear, erlang-cherly, erlang-cowlib, erlang-folsom, erlang-goldrush, erlang-ibrowse, erlang-jiffy, erlang-lager, erlang-lhttpc, erlang-meck, erlang-p1-cache-tab, erlang-p1-iconv, erlang-p1-logger, erlang-p1-mysql, erlang-p1-pam, erlang-p1-pgsql, erlang-p1-sip, erlang-p1-stringprep, erlang-p1-stun, erlang-p1-tls, erlang-p1-utils, erlang-p1-xml, erlang-p1-yaml, erlang-p1-zlib, erlang-ranch, erlang-redis-client, erlang-uuid, freecontact, givaro, glade, gnome-shell, gupnp, gvfs, htseq, jags, jana, knot, libconfig, libkolab, libmatio, libvsqlitepp, mpmath, octave-zenity, openigtlink, paman, pisa, pynifti, qof, ruby-blankslate, ruby-xml-simple, timingframework, trace-cmd, tsung, wings3d, xdg-user-dirs, xz-utils, zpspell. The following packages became reproducible after getting fixed:

• apr/1.5.2-3 by Stefan Fritsch.
• aprx/2.08.svn593+dfsg-2 uploaded by Colin Tuckley, original patch by Chris Lamb.
• blkreplay/1.0-3 uploaded by Andrew Shadura, patch by Dhole.
• cal3d/0.11.0-6 uploaded by Manuel A. Fernandez Montecelo, patch by akira.
• cgsi-gsoap/1.3.8-1 by Mattias Ellert.
• eyefiserver/2.4+dfsg-1 by Jean-Michel Vourg re.
• gnujump/1.0.8-3 uploaded by Evgeni Golov, original patch by Chris Lamb.
• hkgerman/1:2-29 by Roland Rosenfeld.
• jove/4.16.0.73-4 by Cord Beermann.
• libevhtp/1.2.10-3 by Vincent Bernat.
• libmkdoc-xml-perl/0.75-4 uploaded by gregor herrmann, original patch by Niko Tyni.
• libparse-debianchangelog-perl/1.2.0-6 by Niko Tyni.
• librostlab-blast/1.0.1-5 uploaded by Andreas Tille, original patch by Chris Lamb.
• libxray-absorption-perl/3.0.1-3 uploaded by gregor herrmann, original patch by Niko Tyni.
• lua-penlight/1.3.2-2 by Enrico Tassi.
• mosquitto/1.4.3-1 by Roger A. Light.
• nagios-plugins-contrib/15.20150818 by Jan Wagner and Bernd Zeimetz.
• nn/6.7.3-10 uploaded by Cord Beermann, original patch by Chris Lamb.
• pybik/2.1-1 by B. Clausius.
• pyepr/0.9.3-1 uploaded by Antonio Valentino, original patch by Juan Picca.
• python-xlrd/0.9.4-1 by Vincent Bernat.
• transmissionrpc/0.11-2 uploaded by Vincent Bernat, original patch by Juan Picca.
• unoconv/0.7-1.1 sponsored by Vincent Bernat, fix by Dhole.
• vim-latexsuite/20141116.812-1 uploaded by Johann Felix Soden, original patch by Chris Lamb.
• volk/1.0.2-2 by A. Maitland Bottoms.
• xbmc/2:13.2+dfsg1-5 by Balint Reczey.
• xdotool/1:3.20150503.1-2 uploaded by Daniel Kahn Gillmor, initial patch by Chris Lamb.
• xfig/1:3.2.5.c-5 by Roland Rosenfeld.
• xfireworks/1.3-10 uploaded by Yukiharu YABUKI, original patch by Chris Lamb.
• xul-ext-monkeysphere/0.8-2 uploaded by Daniel Kahn Gillmor, original patch by Dhole.

Uploads that might have fixed reproducibility issues:

• brian/1.4.1-3 uploaded by Yaroslav Halchenko, original patch by Juan Picca.
• opennebula/4.12.3+dfsg-1 by Dmitry Smirnov.
• pcsx2/1.3.1-1008-g9f291a6+dfsg-1 by Miguel A. Col n V lez.
• webassets/3:0.11-1 uploaded by Agustin Henze, original patch by Reiner Herrmann.

Some uploads fixed some reproducibility issues but not all of them:

• apache2/2.4.16-3 uploaded by Stefan Fritsch, original patch by Jean-Michel Vourg re.
• gerris/20131206+dfsg-6 uploaded by Anton Gladky, original patch by Reiner Herrmann.
• kodi/15.1+dfsg1-1 by Balint Reczey.
• zshdb/0.05+git20101031-4 uploaded by Iain R. Learmonth, original patch by Chris Lamb.

Patches submitted which have not made their way to the archive yet:

• #795861 on fakeroot by Val Lorentz: set the mtime of all files to the time of the last debian/changelog entry.
• #795870 on fatresize by Chris Lamb: set build date to the time of the latest debian/changelog entry.
• #795945 on projectl by Reiner Herrmann: sort with LC_ALL set to C.
• #795977 on dahdi-tools by Dhole: set the timezone to UTC before calling asciidoc.
• #795981 on x11proto-input by Dhole: set the timezone to UTC before calling asciidoc.
• #795983 on dbusada by Dhole: set the timezone to UTC before calling asciidoc.
• #795984 on postgresql-plproxy by Dhole: set the timezone to UTC before calling asciidoc.
• #795985 on xorg by Dhole: set the timezone to UTC before calling asciidoc.
• #795987 on pngcheck by Dhole: set the date in the man pages to the latest debian/changelog entry.
• #795997 on python-babel by Val Lorentz: make build timestamp independent from the timezone and remove the name of the build system locale from the documentation.
• #796092 on a7xpg by Reiner Herrmann: sort with LC_ALL set to C.
• #796212 on bittornado by Chris Lamb: remove umask-varying permissions.
• #796251 on liblucy-perl by Niko Tyni: generate lib/Lucy.xs in a deterministic order.
• #796271 on tcsh by Reiner Herrmann: sort with LC_ALL set to C.
• #796275 on hspell by Reiner Herrmann: remove timestamp from aff files generated by mk_he_affix.
• #796324 on fftw3 by Reiner Herrmann: remove date from documentation files.
• #796335 on nasm by Val Lorentz: remove extra timestamps from the build system.
• #796360 on libical by Chris Lamb: removes randomess caused Perl in generated icalderivedvalue.c.
• #796375 on wcd by Dhole: set the date in the man pages to the latest debian/changelog entry.
• #796376 on mapivi by Dhole: set the date in the man pages to the latest debian/changelog entry.
• #796527 on vserver-debiantools by Dhole: set the date in the man pages to the latest debian/changelog entry.

St phane Glondu reported two issues regarding embedded build date in omake and cduce. Aur lien Jarno submitted a fix for the breakage of make-dfsg test suite. As binutils now creates deterministic libraries by default, Aur lien's patch makes use of a wrapper to give the U flag to ar. Reiner Herrmann reported an issue with pound which embeds random dhparams in its code during the build. Better solutions are yet to be found. reproducible.debian.net Package pages on reproducible.debian.net now have a new layout improving readability designed by Mattia Rizzolo, h01ger, and Ulrike. The navigation is now on the left as vertical space is more valuable nowadays. armhf is now enabled on all pages except the dashboard. Actual tests on armhf are expected to start shortly. (Mattia Rizzolo, h01ger) The limit on how many packages people can schedule using the reschedule script on Alioth has been bumped to 200. (h01ger) mod_rewrite is now used instead of JavaScript for the form in the dashboard. (h01ger) Following the rename of the software, debbindiff has mostly been replaced by either diffoscope or differences in generated HTML and IRC notification output. Connections to UDD have been made more robust. (Mattia Rizzolo) diffoscope development diffoscope version 31 was released on August 21^st. This version improves fuzzy-matching by using the tlsh algorithm instead of ssdeep. New command line options are available: --max-diff-input-lines and --max-diff-block-lines to override limits on diff input and output (Reiner Herrmann), --debugger to dump the user into pdb in case of crashes (Mattia Rizzolo). jar archives should now be detected properly (Reiner Herrman). Several general code cleanups were also done by Chris Lamb. strip-nondeterminism development Andrew Ayer released strip-nondeterminism version 0.010-1. Java properties file in jar should now be detected more accurately. A missing dependency spotted by St phane Glondu has been added. Testing directory ordering issues: disorderfs During the reproducible builds workshop at DebConf, participants identified that we were still short of a good way to test variations on filesystem behaviors (e.g. file ordering or disk usage). Andrew Ayer took a couple of hours to create disorderfs. Based on FUSE, disorderfs in an overlay filesystem that will mount the content of a directory at another location. For this first version, it will make the order in which files appear in a directory random. Documentation update Dhole documented how to implement support for SOURCE_DATE_EPOCH in Python, bash, Makefiles, CMake, and C. Chris Lamb started to convert the wiki page describing SOURCE_DATE_EPOCH into a Freedesktop-like specification in the hope that it will convince more upstream to adopt it. Package reviews 44 reviews have been removed, 192 added and 77 updated this week. New issues identified this week: locale_dependent_order_in_devlibs_depends, randomness_in_ocaml_startup_files, randomness_in_ocaml_packed_libraries, randomness_in_ocaml_custom_executables, undeterministic_symlinking_by_rdfind, random_build_path_by_golang_compiler, and images_in_pdf_generated_by_latex. 117 new FTBFS bugs have been reported by Chris Lamb, Chris West (Faux), and Niko Tyni. Misc. Some reproducibility issues might face us very late. Chris Lamb noticed that the test suite for python-pykmip was now failing because its test certificates have expired. Let's hope no packages are hiding a certificate valid for 10 years somewhere in their source! Pictures courtesy and copyright of Debian's own paparazzi: Aigars Mahinovs.