Search Results: "ed"

1 September 2014

Peter Palfrader: Fun and Profit with lirc

= Fun and Profit with lirc == Getting the basics A couple weeks ago I got myself a small USB Infrared Transceiver from the people at iguanaworks. It comes in different models and I got the dual socket one that allows me to hook up external IR emitters. The goal was to remote control my stereo from my desktop machine, so using wired IR blasters gives me the flexibility I need with the wiring. They provide Debian packages built for some version of Ubunutu from their website. I wanted to build them from source, so apt-get source from their repository it is. The build process of the package is pretty broken -- it assumes there already is an iguanair user for instance. If somebody could package this up properly for Debian that'd be real nice. And who knows, maybe upstream would appreciate that as well. At first glance the software looks free enough. Once iguanair has been built and installed, lirc needs a recompile -- it will pick up the iguanair library automatically. Their Getting Started docs are actually pretty good. == Learning the IR codes Anyway, once the software was set up, I needed the IR-codes to send to my Denon. There are a couple of databases for varios remote controls and receivers on the internet, but I didn't find a single entry for my old Denon AVR-1600RD. Fortunately lirc alls you to learn codes off a remote control you already have, and since the iguana device also comes with a receiver, I could use irrecord to get the needed magic bytes for commands like power on/off, mute, volume up/down. This actually worked quite well, the only problem was realizing that the IR blasters are really picky about being properly aligned and close to the receiver (my Denon). Once I got that right, all the recorded codes worked. lircd.conf for Denon AVR-1600RD == Putting it all together I can now use this to mute my stereo using irsend send_once denon KEY_MUTE for instance. What I also wanted to get out of this was that the stereo should be shut off automatically when my machine goes to sleep, or when I haven't used it in a while. Since my Denon only has a power toggle command and does not appear to have a discrete power-off command -- at least I don't know it -- I needed something on my system to keep state, and it means I no longer should use my real remote control or else things will get out of sync. I have written a small wrapper script that does this for me -- stereo. It's in /usr/local/bin . === Initialisation On boot, the script creates its state file when called with the init command. There is a small init script that takes care of this, as well as turning off the stereo when the machine reboots or powers off. === Power off on suspend In addition to powering off the stereo when the machine goes down, I also want it to do that when it goes to sleep. Enter /etc/pm/sleep.d/20 stereo . === Power off on idle Furthermore, I run the script out of cron every 5 minutes - to see if anything is using the alsa device. If there isn't for half an hour the stereo gets turned off. Crontab entry: */5 * * * * /usr/local/bin/stereo off-if-idle === Manually controlling it And last not least I have integrated it into my xbindkeys config. I am abusing a couple special keys that I never ever use. Here's the snippet from my ~/.xbindkeysrc : "stereo mute" XF86HomePage "stereo vol-" XF86Search "stereo vol+" XF86Mail "stereo toggle" c:193 "stereo touch" c:192 Cheers,

Christian Perrier: Bug #760000

Ren Mayorga reported Debian bug #760000 on Saturday August 30th, against the pyfribidi package. Bug #750000 was reported as of May 31th: nearly exactly 3 months for 10,000 bugs. The bug rate increased a little bit during the last weeks, probably because of the freeze approaching. We're therefore getting more clues about the time when bug #800000 for which we have bets. will be reported. At current rate, this should happen in one year. So, the current favorites are Knuth Posern or Kartik Mistry. Still, David Pr vot, Andreas Tille, Elmar Heeb and Rafael Laboissiere have their chances, too, if the bug rate increases (I'll watch you guys: any MBF by one of you will be suspect...:-)).

31 August 2014

Junichi Uekawa: I was staring at qemu source for a while last month.

I was staring at qemu source for a while last month. There's a lot of things that I don't understand about the codebase. There's a race but it's hard to tell why a SIGSEGV was received.

Tim Retout: Website revamp

This weekend I moved my blog to a different server. This meant I could: I've tested it, and it's working. I'm hoping that I can swap out the Node.js modules one-by-one for the Debian-packaged versions.

Stefano Zacchiroli: debsources hacking

Debsources now has a HACKING file Here at DebConf14 I have given a few talks. The second one has been a technical talk about recent and future developments on Debsources. Both the talk slides and video are available. After the talk, various DebConf participants have approached me and started hacking on Debsources, which is awesome! As a result of their work, new shiny features will probably be announced shortly. Stay tuned. When discussing with new contributors (hi Luciano, Raphael!), though, it quickly became clear that getting started with Debsources hacking wasn't particularly easy. In particular, doing a local deployment for testing purposes might be intimidating, due to the need of having a (partial) source mirror and whatnot. To fix that, I have now written a HACKING file for Debsources, which you can find at top-level in the Git repo. Happy Debsources hacking!

Thorsten Alteholz: My Debian activities in August 2014

FTP assistant By pure chance I was able to accept 237 packages, the same number as last month. 33 times I contacted the maintainer to ask a question about a package and 55 times I had to reject a package. The reject number increased a bit as I also worked on packages that already got a note but had not been fully processed. In contrast I only filed three serious bugs this month. Currently there are about 200 packages still waiting in the NEW queue As the freeze for Jessie comes closer every day, I wonder whether all of them can be processed in time. So I don t mind if every maintainer checks the package again and maybe uploads an improved version that can be processed faster. Squeeze LTS This was my second month that I did some work for the Squeeze LTS initiative, started by Raphael Hertzog at Freexian All in all I got assigned a workload of 16.5h for August. I spent these hours to upload new versions of As last month I prepared these uploads on the basis of the corresponding DSAs for Wheezy. For these packages backporting the Wheezy patches to Squeeze was rather easy. I also had a look at python-django and eglibc. Although the python-django patches apply now, the package fails some tests and these issues need some further investigation. In case of eglibc, my small pbuilder didn t have enough resources and trying to build the package resulted in a full disk after more than three hours of work. For PHP5 Ond ej Sur (the real maintainer) suggested to use point releases of upstream instead of applying only patches. I am curious about how much effort is needed for this approach. Stay tuned, next month you will be told more details! Anyway, this is still a lot of fun and I hope I can finish python-django, eglibc and php5 in September. Other packages This month my meep packages plus mpb have been part of a small hdf5 transition. All five packages needed a small patch and a new upload. As the patch was already provided by Gilles Filippini, this was done rather quickly. Support If you would like to support my Debian work you could either be part of the Freexian initiative (see above) or consider to send some bitcoins to 1JHnNpbgzxkoNexeXsTUGS6qUp5P88vHej. Contact me at donation@alteholz.eu if you prefer another way to donate. Every kind of support is most appreciated.

Ritesh Raj Sarraf: apt-offline 1.4

apt-offline 1.4 has been released [1]. This is a minor bug fix release. In fact, one feature, offline bug reports (--bug-reports), has been dropped for now. The Debian BTS interface seems to have changed over time and the older debianbts.py module (that used the CGI interface) does not seem to work anymore. The current debbugs.py module seems to have switched to the SOAP interface. There are a lot of changes going on personally, I just haven't had the time to spend. If anyone would like to help, please reach out to me. We need to use the new debbugs.py module. And it should be cross-platform. Also, thanks to Hans-Christoph Steiner for providing the bash completion script. [1] https://alioth.debian.org/projects/apt-offline/

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Russell Coker: Links August 2014

Matt Palmer wrote a good overview of DNSSEC [1]. Sociological Images has an interesting article making the case for phasing out the US $0.01 coin [2]. The Australian $0.01 and $0.02 coins were worth much more when they were phased out. Multiplicity is a board game that s designed to address some of the failings of SimCity type games [3]. I haven t played it yet but the page describing it is interesting. Carlos Buento s article about the Mirrortocracy has some interesting insights into the flawed hiring culture of Silicon Valley [4]. Adam Bryant wrote an interesting article for NY Times about Google s experiments with big data and hiring [5]. Among other things it seems that grades and test results have no correlation with job performance. Jennifer Chesters from the University of Canberra wrote an insightful article about the results of Australian private schools [6]. Her research indicates that kids who go to private schools are more likely to complete year 12 and university but they don t end up earning more. Kiwix is an offline Wikipedia reader for Android, needs 9.5G of storage space for the database [7]. Melanie Poole wrote an informative article for Mamamia about the evil World Congress of Families and their connections to the Australian government [8]. The BBC has a great interactive web site about how big space is [9]. The Raspberry Pi Spy has an interesting article about automating Minecraft with Python [10]. Wired has an interesting article about the Bittorrent Sync platform for distributing encrypted data [11]. It s apparently like Dropbox but encrypted and decentralised. Also it supports applications on top of it which can offer social networking functions among other things. ABC news has an interesting article about the failure to diagnose girls with Autism [12]. The AbbottsLies.com.au site catalogs the lies of Tony Abbott [13]. There s a lot of work in keeping up with that. Racialicious.com has an interesting article about Moff s Law about discussion of media in which someone says why do you have to analyze it [14]. Paul Rosenberg wrote an insightful article about conservative racism in the US, it s a must-read [15]. Salon has an interesting and amusing article about a photography project where 100 people were tased by their loved ones [16]. Watch the videos.

Steve Kemp: A diversion - The National Health Service

Today we have a little diversion to talk about the National Health Service. The NHS is the publicly funded healthcare system in the UK.
Actually there are four such services in the UK, only one of which has this name:
  • The national health service (England)
  • Health and Social Care in Northern Ireland.
  • NHS Scotland.
  • NHS Wales.
In theory this doesn't matter, if you're in the UK and you break your leg you get carried to a hospital and you get treated. There are differences in policies because different rules apply, but the basic stuff "free health care" applies to all locations. (Differences? In Scotland you get eye-tests for free, in England you pay.)
My wife works as an accident & emergency doctor, and has recently changed jobs. Hearing her talk about her work is fascinating. The hospitals she's worked in (Dundee, Perth, Kirkcaldy, Edinburgh, Livingstone) are interesting places. During the week things are usually reasonably quiet, and during the weekend things get significantly more busy. (This might mean there are 20 doctors to hand, versus three at quieter times.) Weekends are busy largely because people fall down hills, get drunk and fight, and are at home rather than at work - where 90% of accidents occur. Of course even a "quiet" week can be busy, because folk will have heart-attacks round the clock, and somebody somewhere will always be playing with a power tool, a ladder, or both! So what was the point of this post? Well she's recently transferred to working for a childrens hospital (still in A&E) and the patiences are so very different. I expected the injuries/patients she'd see to differ. Few 10 year olds will arrive drunk (though it does happen), and few adults fall out of trees, or eat washing machine detergent, but talking to her about her day when she returns home is fascinating how many things are completely different from how I expected. Adults come to hospital mostly because they're sick, injured, or drunk. Children come to hospital mostly because their parents are paranoid. A child has a rash? Doctors are closed? Lets go to the emergency ward! A child has fallen out of a tree and has a bruise, a lump, or complains of pain? Doctors are closed? Lets go to the emergency ward! I've not kept statistics, though I wish I could, but it seems that she can go 3-5 days between seeing an actually injured or chronicly-sick child. It's the first-time-parents who bring kids in when they don't need to. Understandable, completely understandable, but at the same time I'm sure it is more than a little frustrating for all involved. Finally one thing I've learned, which seems completely stupid, is the NHS-Scotland approach to recruitment. You apply for a role, such as "A&E doctor" and after an interview, etc, you get told "You've been accepted - you will now work in Glasgow". In short you apply for a post, and then get told where it will be based afterward. There's no ability to say "I'd like to be a Doctor in city X - where I live", you apply, and get told where it is post-acceptance. If it is 100+ miles away you either choose to commute, or decline and go through the process again. This has lead to Kirsi working in hospitals with a radius of about 100km from the city we live in, and has meant she's had to turn down several posts. And that is all I have to say about the NHS for the moment, except for the implicit pity for people who have to pay (inflated and life-changing) prices for things in other countries.

Lucas Nussbaum: Debian trivia

After an intensive evening of brainstorming by the 5th floor cabal, I am happy to release the very first version of the Debian Trivia, modeled after the famous TCP/IP Drinking Game. Only the questions are listed here maybe they should go (with the answers) into a package? Anyone willing to co-maintain? Any suggestions for additional questions?

Alexander Wirt: cgit on alioth.debian.org

Recently I was doing some work on the alioth infrastructure like fixing things or cleaning up things. One of the more visible things I done was the switch from gitweb to cgit. cgit is a lot of faster and looks better than gitweb. The list of repositories is generated every hour. The move also has the nice effect that user repositories are available via the cgit index again. I don t plan to disable the old gitweb, but I created a bunch of redirect rules that - hopefully - redirect most use cases of gitweb to the equivalent cgit url. If I broke something, please tell me, if I missed a common use case, please tell me. You can usually reach me on #alioth@oftc or via mail (formorer@d.o) People also asked me to upload my cgit package to Debian, the package is now waiting in NEW. Thanks to Nicolas Dandrimont (olasd) we also have a patch included that generates proper HTTP returncodes if repos doesn t exist.

30 August 2014

Francois Marier: Outsourcing your webapp maintenance to Debian

Modern web applications are much more complicated than the simple Perl CGI scripts or PHP pages of the past. They usually start with a framework and include lots of external components both on the front-end and on the back-end. Here's an example from the Node.js back-end of a real application:
$ npm list   wc -l
256
What if one of these 256 external components has a security vulnerability? How would you know and what would you do if of your direct dependencies had a hard-coded dependency on the vulnerable version? It's a real problem and of course one way to avoid this is to write everything yourself. But that's neither realistic nor desirable. However, it's not a new problem. It was solved years ago by Linux distributions for C and C++ applications. For some reason though, this learning has not propagated to the web where the standard approach seems to be to "statically link everything". What if we could build on the work done by Debian maintainers and the security team?

Case study - the Libravatar project As a way of discussing a different approach to the problem of dependency management in web applications, let me describe the decisions made by the Libravatar project.

Description Libravatar is a federated and free software alternative to the Gravatar profile photo hosting site. From a developer point of view, it's a fairly simple stack: The service is split between the master node, where you create an account and upload your avatar, and a few mirrors, which serve the photos to third-party sites. Like with Gravatar, sites wanting to display images don't have to worry about a complicated protocol. In a nutshell, all that a site needs to do is hash the user's email and add that hash to a base URL. Where the federation kicks in is that every email domain is able to specify a different base URL via an SRV record in DNS. For example, francois@debian.org hashes to 7cc352a2907216992f0f16d2af50b070 and so the full URL is:
http://cdn.libravatar.org/avatar/7cc352a2907216992f0f16d2af50b070
whereas francois@fmarier.org hashes to 0110e86fdb31486c22dd381326d99de9 and the full URL is:
http://fmarier.org/avatar/0110e86fdb31486c22dd381326d99de9
due to the presence of an SRV record on fmarier.org.

Ground rules The main rules that the project follows is to:
  1. only use Python libraries that are in Debian
  2. use the versions present in the latest stable release (including backports)

Deployment using packages In addition to these rules around dependencies, we decided to treat the application as if it were going to be uploaded to Debian:
  • It includes an "upstream" Makefile which minifies CSS and JavaScript, gzips them, and compiles PO files (i.e. a "build" step).
  • The Makefile includes a test target which runs the unit tests and some lint checks (pylint, pyflakes and pep8).
  • Debian packages are produced to encode the dependencies in the standard way as well as to run various setup commands in maintainer scripts and install cron jobs.
  • The project runs its own package repository using reprepro to easily distribute these custom packages.
  • In order to update the repository and the packages installed on servers that we control, we use fabric, which is basically a fancy way to run commands over ssh.
  • Mirrors can simply add our repository to their apt sources.list and upgrade Libravatar packages at the same time as their system packages.

Results Overall, this approach has been quite successful and Libravatar has been a very low-maintenance service to run. The ground rules have however limited our choice of libraries. For example, to talk to our queuing system, we had to use the raw Python bindings to the C Gearman library instead of being able to use a nice pythonic library which wasn't in Debian squeeze at the time. There is of course always the possibility of packaging a missing library for Debian and maintaining a backport of it until the next Debian release. This wouldn't be a lot of work considering the fact that responsible bundling of a library would normally force you to follow its releases closely and keep any dependencies up to date, so you may as well share the result of that effort. But in the end, it turns out that there is a lot of Python stuff already in Debian and we haven't had to package anything new yet. Another thing that was somewhat scary, due to the number of packages that were going to get bumped to a new major version, was the upgrade from squeeze to wheezy. It turned out however that it was surprisingly easy to upgrade to wheezy's version of Django, Apache and Postgres. It may be a problem next time, but all that means is that you have to set a day aside every 2 years to bring everything up to date.

Problems The main problem we ran into is that we optimized for sysadmins and unfortunately made it harder for new developers to setup their environment. That's not very good from the point of view of welcoming new contributors as there is quite a bit of friction in preparing and testing your first patch. That's why we're looking at encoding our setup instructions into a Vagrant script so that new contributors can get started quickly. Another problem we faced is that because we use the Debian version of jQuery and minify our own JavaScript files in the build step of the Makefile, we were affected by the removal from that package of the minified version of jQuery. In our setup, there is no way to minify JavaScript files that are provided by other packages and so the only way to fix this would be to fork the package in our repository or (preferably) to work with the Debian maintainer and get it fixed globally in Debian. One thing worth noting is that while the Django project is very good at issuing backwards-compatible fixes for security issues, sometimes there is no way around disabling broken features. In practice, this means that we cannot run unattended-upgrades on our main server in case something breaks. Instead, we make use of apticron to automatically receive email reminders for any outstanding package updates. On that topic, it can occasionally take a while for security updates to be released in Debian, but this usually falls into one of two cases:
  1. You either notice because you're already tracking releases pretty well and therefore could help Debian with backporting of fixes and/or testing;
  2. or you don't notice because it has slipped through the cracks or there simply are too many potential things to keep track of, in which case the fact that it eventually gets fixed without your intervention is a huge improvement.
Finally, relying too much on Debian packaging does prevent Fedora users (a project that also makes use of Libravatar) from easily contributing mirrors. Though if we had a concrete offer, we would certainly look into creating the appropriate RPMs.

Is it realistic? It turns out that I'm not the only one who thought about this approach, which has been named "debops". The same day that my talk was announced on the DebConf website, someone emailed me saying that he had instituted the exact same rules at his company, which operates a large Django-based web application in the US and Russia. It was pretty impressive to read about a real business coming to the same conclusions and using the same approach (i.e. system libraries, deployment packages) as Libravatar. Regardless of this though, I think there is a class of applications that are particularly well-suited for the approach we've just described. If a web application is not your full-time job and you want to minimize the amount of work required to keep it running, then it's a good investment to restrict your options and leverage the work of the Debian community to simplify your maintenance burden. The second criterion I would look at is framework maturity. Given the 2-3 year release cycle of stable distributions, this approach is more likely to work with a mature framework like Django. After all, you probably wouldn't compile Apache from source, but until recently building Node.js from source was the preferred option as it was changing so quickly. While it goes against conventional wisdom, relying on system libraries is a sustainable approach you should at least consider in your next project. After all, there is a real cost in bundling and keeping up with external dependencies. This blog post is based on a talk I gave at DebConf 14: slides, video.

John Goerzen: 2AM to Seattle

Monday morning, 1:45AM. Laura and I walk into the boys room. We turn on the light. Nothing happens. (They re sound sleepers.) Boys, it s time to get up to go get on the train! Four eyes pop open. Yay! Oh I m so excited! And then, Meow! (They enjoy playing with their stuffed cats that Laura got them for Christmas.) Before long, it was out the door to the train station. We even had time to stop at a donut shop along the way. We climbed into our family bedroom (a sleeping car room on Amtrak specifically designed for families of four), and as the train started to move, the excitement of what was going on crept in. Yes, it s 2:42AM, but these are two happy boys: 2014-08-04 02 Jacob and Oliver love trains, and this was the beginning of a 3-day train trip from Newton to Seattle that would take us through Kansas, Colorado, the Rocky Mountains of New Mexico, Arizona, Los Angeles, up the California coast, through the Cascades, and on to Seattle. Whew! Here we are later that morning before breakfast: IMG_3776 Here s our train at a station stop in La Junta, CO: IMG_3791 And at the beautiful small mountain town of Raton, NM: IMG_3805 Some of the passing scenery in New Mexico: IMG_3828 Through it all, we found many things to pass the time. I don t think anybody was bored. I took the boys exploring the train several times we d walk from one end to the other and see what all was there. There was always the dining car for our meals, the lounge car for watching the passing scenery, and on the Coast Starlight, the Pacific Parlor Car. Here we are getting ready for breakfast one morning. IMG_3830 Getting to select meals and order in the train restaurant was a big deal for the boys. IMG_3832 Laura brought one of her origami books, which even managed to pull the boys away from the passing scenery in the lounge car for quite some time. IMG_3848 Origami is serious business: IMG_3869 They had some fun wrapping themselves around my feet and challenging me to move. And were delighted when I could move even though they were trying to weight me down! IMG_3880 Several games of Uno were played, but even those sometimes couldn t compete with the passing scenery: IMG_3898 The Coast Starlight features the Pacific Parlor Car, which was built over 50 years ago for the Santa Fe Hi-Level trains. They ve been updated; the upper level is a lounge and small restaurant, and the lower level has been turned into a small theater. They show movies in there twice a day, but most of the time, the place is empty. A great place to go with little boys to run around and play games. IMG_3896 The boys and I sort of invented a new game: roadrunner and coyote, loosely based on the old Looney Tunes cartoons. Jacob and Oliver would be roadrunners, running around and yelling MEEP MEEP! Meanwhile, I was the coyote, who would try to catch them even briefly succeeding sometimes but ultimately fail in some hilarious way. It burned a lot of energy. And, of course, the parlor car was good for scenery-watching too: IMG_3908 We were right along the Pacific Ocean for several hours sometimes there would be a highway or a town between us and the beach, but usually there was nothing at all between us and the coast. It was beautiful to watch the jagged coastline go by, to gaze out onto the ocean, watching the birds apparently so beautiful that I didn t even think to take some photos. Laura s parents live in California, and took a connecting train. I had arranged for them to have a sleeping car room near ours, so for the last day of the trip, we had a group of 6. Here are the boys with their grandparents at lunch Wednesday: 2014-08-06 11 We stepped off the train in Seattle into beautiful King Street Station. P8100197 Our first day in Seattle was a quiet day of not too much. Laura s relatives live near Lake Washington, so we went out there to play. The boys enjoyed gathering black rocks along the shore. IMG_3956 We went blackberry picking after that filled up buckets for a cobbler. The next day, we rode the Seattle Monorail. The boys have been talking about this for months a kind of train they ve never been on. That was the biggest thing in their minds that they were waiting for. They got to ride in the very front, by the operator. P8080073 Nice view from up there. P8080078 We walked through the Pike Market I hadn t been in such a large and crowded place like that since I was in Guadalajara: P8080019 At the Seattle Aquarium, we all had a great time checking out all the exhibits. The please touch one was a particular hit. P8080038 Walking underneath the salmon tank was fun too. We spent a couple of days doing things closer to downtown. Laura s cousin works at MOHAI, the Museum of History and Industry, so we spent a morning there. The boys particularly enjoyed the old periscope mounted to the top of the building, and the exhibit on chocolate (of course!) P8100146 They love any kind of transportation, so of course we had to get a ride on the Seattle Streetcar that comes by MOHAI. P8090094 All weekend long, we had been noticing the seaplanes taking off from Lake Washington and Lake Union (near MOHAI). So finally I decided to investigate, and one morning while Laura was doing things with her cousin, the boys and I took a short seaplane ride from one lake to another, and then rode every method of transportation we could except for ferries (we did that the next day). Here is our Kenmore Air plane: P8100100 The view of Lake Washington from 1000 feet was beautiful: P8100109 I think we got a better view than the Space Needle, and it probably cost about the same anyhow. P8100117 After splashdown, we took the streetcar to a place where we could eat lunch right by the monorail tracks. Then we rode the monorail again. Then we caught a train (it went underground a bit so it was a subway to them!) and rode it a few blocks. There is even scenery underground, it seems. P8100151 We rode a bus back, and saved one last adventure for the next day: a ferry to Bainbridge Island. 2014-08-11 14 2014-08-11 16 Laura and I even got some time to ourselves to go have lunch at an amazing Greek restaurant to celebrate a year since we got engaged. It s amazing to think that, by now, it s only a few months until our wedding anniversary too! There are many special memories of the weekend I could mention visiting with Laura s family, watching the boys play with her uncle s pipe organ (it s in his house!), watching the boys play with their grandparents, having all six of us on the train for a day, flying paper airplanes off the balcony, enjoying the cool breeze on the ferry and the beautiful mountains behind the lake. One of my favorites is waking up to high-pitched Meow? Meow meow meow! Wake up, brother! sorts of sounds. There was so much cat-play on the trip, and it was cute to hear. I have the feeling we won t hear things like that much more. So many times on the trip I heard, Oh dad, I am so excited! I never get tired of hearing that. And, of course, I was excited, too.

Joachim Breitner: DebConf 14

I m writing this blog post on the plane from Portland towards Europe (which I now can!), using the remaining battery live after having watched one of the DebConf talks that I missed. (It was the systemd talk, which was good and interesting, but maybe I should have watched one of the power management talks, as my battery is running down faster than it should be, I believe.) I mostly enjoyed this year s DebConf. I must admit that I did not come very prepared: I had neither something urgent to hack on, nor important things to discuss with the other attendees, so in a way I had a slow start. I also felt a bit out of touch with the project, both personally and technically: In previous DebConfs, I had more interest in many different corners of the project, and also came with more naive enthusiasm. After more than 10 years in the project, I see a few things more realistic and also more relaxed, and don t react on Wouldn t it be cool to have crazy idea very easily any more. And then I mostly focus on Haskell packaging (and related tooling, which sometimes is also relevant and useful to others) these days, which is not very interesting to most others. But in the end I did get to do some useful hacking, heard a few interesting talks and even got a bit excited: I created a new tool to schedule binNMUs for Haskell packages which is quite generic (configured by just a regular expression), so that it can and will be used by the OCaml team as well, and who knows who else will start using hash-based virtual ABI packages in the future... It runs via a cron job on people.debian.org to produce output for Haskell and for OCaml, based on data pulled via HTTP. If you are a Debian developer and want up-to-date results, log into wuiet.debian.org and run ~nomeata/binNMUs --sql; it then uses the projectb and wanna-build databases directly. Thanks to the ftp team for opening up incoming.debian.org, by the way! Unsurprisingly, I also held a talk on Haskell and Debian (slides available). I talked a bit too long and we had too little time for discussion, but in any case not all discussion would have fitted in 45 minutes. The question of which packages from Hackage should be added to Debian and which not is still undecided (which means we carry on packaging what we happen to want in Debian for whatever reason). I guess the better our tooling gets (see the next section), the more easily we can support more and more packages. I am quite excited by and supportive of Enrico s agenda to remove boilerplate data from the debian/ directories and relying on autodebianization tools. We have such a tool for Haskell package, cabal-debian, but it is unofficial, i.e. neither created by us nor fully endorsed. I want to change that, so I got in touch with the upstream maintainer and we want to get it into shape for producing perfect Debian packages, if the upstream provided meta data is perfect. I d like to see the Debian Haskell Group to follows Enrico s plan to its extreme conclusion, and this way drive innovation in Debian in general. We ll see how that goes. Besides all the technical program I enjoyed the obligatory games of Mao and Werewolves. I also got to dance! On Saturday night, I found a small but welcoming Swing-In-The-Park event where I could dance a few steps of Lindy Hop. And on Tuesday night, Vagrant Cascadian took us (well, three of us) to a blues dancing night, which I greatly enjoyed: The style was so improvisation-friendly that despite having missed the introduction and never having danced Blues before I could jump right in. And in contrast to social dances in Germany, where it is often announced that the girls are also invited to ask the boys, but then it is still mostly the boys who have to ask, here I took only half a minute of standing at the side until I got asked to dance. In retrospect I should have skipped the HP reception and went there directly... I m not heading home at the moment, but will travel directly to G teborg to attend ICFP 2014. I hope the (usually worse) west-to-east jet lag will not prevent me from enjoying that as much as I could.

Gergely Nagy: Happy

For the past decade or so, I wasn't exactly happy. I struggled with low self esteem, likely bordered on depression at times. I disappointed friends, family and most of all, myself. There were times I not only disliked the person I was, but hated it. This wasn't healthy, nor forward-looking, I knew that all along, and that made the situation even worse. I tried to maintain a more enthusiastic mask, pretended that nothing's wrong. Being fully aware that there actually is nothing terribly wrong, while still feeling worthless, just added insult to injury.In the past few years, things started to improve. I had a job, things to care about, things to feel passionate about, people around me who knew nothing about the shadows on my heart, yet still smiled, still supported me. But years of self loathing does not disappear overnight.Then one day, some six months ago, my world turned upside down. Years of disappointment, hate and loathing - poof, gone. Today, I'm happy. This is something I have not been able to tell myself in all honesty in this century yet (except maybe for very brief periods of time, when I was happy for someone else).[Engaged]A little over six months ago, I met someone, someone I could open up to. I still remember the first hour, where we talked about our own shortcomings and bad habits. At the end of the day, when She ordered me a crazy-pancake (a pancake with half a dozen random fillings), I felt happy. She is everything I could ever wish for, and more. She isn't just the woman I love, with whom I'll say the words in a couple of months. She's much more than a partner, a friend a soul-mate combined in one person. She is my inspiration, my role model and my Guardian Angel too.I no longer feel worthless, nor inadequate. I am disappointed with myself no more. I do not hate, I do not loathe, and past mistakes, past feelings seem so far away! I can share everything with Her, She does not judge, nor condemn: she supports and helps. With Her, I am happy. With Her, I am who I wanted myself to be. With Her, I am complete.Thank You.

Matthew Palmer: Chromium tabs crashing and not rendering correctly?

If you ve noticed your chrome/chromium on Linux having problems since you upgraded to somewhere around version 35/36, you re not alone. Thankfully, it s relatively easy to workaround. It will hit people who keep their browser open for a long time, or who have lots of tabs (or if you re like me, and do both). To tell if you re suffering from this particular problem, crack open your ~/.xsession-errors file (or wherever your system logs stdout/stderr from programs running under X), and look for lines that look like this:
[22161:22185:0830/124533:ERROR:shared_memory_posix.cc(231)]
Creating shared memory in /dev/shm/.org.chromium.Chromium.gFTQSy
failed: Too many open files
And
[22161:22185:0830/124601:ERROR:host_shared_bitmap_manager.cc(122)]
Cannot create shared memory buffer
If you see those errors, congratulations! The rest of this blog post will be of use to you. There s probably a myriad of bugs open about this problem, but the one I found was #367037: Shared memory-related tab crash. It turns out there s a file handle leak in the chromium codebase somewhere, relating to shared memory handling. There s no fix available, but the workaround is quite simple: increase the number of files that processes are allowed to have open. System-wide, you can do this by creating a file /etc/security/limits.d/local-nofile.conf, containing this line:
* - nofile 65535
You could also edit /etc/security/limits.conf to contain the same line, if you were so inclined. Note that this will only take effect next time you login, or perhaps even only when you restart X (or, at worst, your entire machine). This doesn t help you if you ve got Chromium already open and you d like to stop it from crashing Right Now (perhaps restarting your machine would be a terrible hardship, causing you to lose your hard-won uptime record), then you can use a magical tool called prlimit. The prlimit syscall is available if you re running a Linux 2.6.36 or later kernel, and running at least glibc 2.13. You ll have a prlimit command line program if you ve got util-linux 2.21 or later. If not, you can use the example source code in the prlimit(2) manpage, changing RLIMIT_CPU to RLIMIT_NOFILE, and then running it like this:
prlimit <PID> 65535 65535
The <PID> argument is taken from the first number in the log messages from .xsession-errors in the example above, it s 22161. And now, you can go back to using your tabs as ersatz bookmarks, like I do.

Dirk Eddelbuettel: BH release 1.54.0-4

Another small new release of our BH package providing Boost headers for use by R is now on CRAN. This one brings a one-file change: the file any.hpp comprising the Boost.Any library --- as requested by a fellow package maintainer needing it for a pending upload to CRAN. No other changes were made.
Changes in version 1.54.0-4 (2014-08-29)
  • Added Boost Any requested by Greg Jeffries for his nabo package
Courtesy of CRANberries, there is also a diffstat report for the most recent release. Comments and suggestions are welcome via the mailing list or issue tracker at the GitHub repo.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

29 August 2014

Steve Kemp: Migration of services and hosts

Yesterday I carried out the upgrade of a Debian host from Squeeze to Wheezy for a friend. I like doing odd-jobs like this as they're generally painless, and when there are problems it is a fun learning experience. I accidentally forgot to check on the status of the MySQL server on that particular host, which was a little embarassing, but later put together a reasonably thorough serverspec recipe to describe how the machine should be setup, which will avoid that problem in the future - Introduction/tutorial here. The more I use serverspec the more I like it. My own personal servers have good rules now:
shelob ~/Repos/git.steve.org.uk/server/testing $ make
..
Finished in 1 minute 6.53 seconds
362 examples, 0 failures
Slow, but comprehensive. In other news I've now migrated every single one of my personal mercurial repositories over to git. I didn't have a particular reason for doing that, but I've started using git more and more for collaboration with others and using two systems felt like an annoyance. That means I no longer have to host two different kinds of repositories, and I can use the excellent gitbucket software on my git repository host. Needless to say I wrote a policy for this host too:
#
#  The host should be wheezy.
#
describe command("lsb_release -d") do
  its(:stdout)   should match /wheezy/  
end
#
# Our gitbucket instance should be running, under runit.
#
describe supervise('gitbucket') do
  its(:status)   should eq 'run'  
end
#
# nginx will proxy to our back-end
#
describe service('nginx') do
  it   should be_enabled    
  it   should be_running    
end
describe port(80) do
  it   should be_listening  
end
#
#  Host should resolve
#
describe host("git.steve.org.uk" ) do
  it   should be_resolvable.by('dns')  
end
Simple stuff, but being able to trigger all these kind of tests, on all my hosts, with one command, is very reassuring.

Jakub Wilk: More spell-checking

Have you ever wanted to use Lintian's spell-checker against arbitrary files? Now you can do it with spellintian:
$ zrun spellintian --picky /usr/share/doc/RFC/best-current-practice/rfc*
/tmp/0qgJD1Xa1Y-rfc1917.txt: amoung -> among
/tmp/kvZtN435CE-rfc3155.txt: transfered -> transferred
/tmp/o093khYE09-rfc3481.txt: unecessary -> unnecessary
/tmp/4P0ux2cZWK-rfc6365.txt: charater -> character
mwic (Misspelled Words In Context) takes a different approach. It uses classic spell-checking libraries (via Enchant), but it groups misspellings and shows them in their contexts. That way you can quickly filter out false-positives, which are very common in technical texts, using visual grep:
$ zrun mwic /usr/share/doc/debian/social-contract.txt.gz
DFSG:
   an Free Software Guidelines (DFSG)
   an Free Software Guidelines (DFSG) part of the
                                ^^^^
Perens:
     Bruce Perens later removed the Debian-spe 
  by Bruce Perens, refined by the other Debian 
           ^^^^^^
Ean, Schuessler:
  community" was suggested by Ean Schuessler. This document was drafted
                              ^^^ ^^^^^^^^^^
GPL:
  The "GPL", "BSD", and "Artistic" lice 
       ^^^
contrib:
  created "contrib" and "non-free" areas in our 
           ^^^^^^^
CDs:
  their CDs. Thus, although non-free wor 
        ^^^

Antti-Juhani Kaijanaho: Licentiate Thesis is now publicly available

My recently accepted Licentiate Thesis, which I posted about a couple of days ago, is now available in JyX. Here is the abstract again for reference: Kaijanaho, Antti-Juhani
The extent of empirical evidence that could inform evidence-based design of programming languages. A systematic mapping study.
Jyv skyl : University of Jyv skyl , 2014, 243 p.
(Jyv skyl Licentiate Theses in Computing,
ISSN 1795-9713; 18)
ISBN 978-951-39-5790-2 (nid.)
ISBN 978-951-39-5791-9 (PDF)
Finnish summary Background: Programming language design is not usually informed by empirical studies. In other fields similar problems have inspired an evidence-based paradigm of practice. Central to it are secondary studies summarizing and consolidating the research literature. Aims: This systematic mapping study looks for empirical research that could inform evidence-based design of programming languages. Method: Manual and keyword-based searches were performed, as was a single round of snowballing. There were 2056 potentially relevant publications, of which 180 were selected for inclusion, because they reported empirical evidence on the efficacy of potential design decisions and were published on or before 2012. A thematic synthesis was created. Results: Included studies span four decades, but activity has been sparse until the last five years or so. The form of conditional statements and loops, as well as the choice between static and dynamic typing have all been studied empirically for efficacy in at least five studies each. Error proneness, programming comprehension, and human effort are the most common forms of efficacy studied. Experimenting with programmer participants is the most popular method. Conclusions: There clearly are language design decisions for which empirical evidence regarding efficacy exists; they may be of some use to language designers, and several of them may be ripe for systematic reviewing. There is concern that the lack of interest generated by studies in this topic area until the recent surge of activity may indicate serious issues in their research approach. Keywords: programming languages, programming language design, evidence-based paradigm, efficacy, research methods, systematic mapping study, thematic synthesis

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