Search Results: "ana"

25 September 2013

Daniel Kahn Gillmor: half a minute for science!

A friend is teaching a class on data analysis. She is building a simple and rough data set for the class to examine, and to spur discussion. You can contribute in half a minute! Here's how:
  1. get a stopwatch or other sort of timer (whatever device you're reading this on probably has such a thing).
  2. start the timer, but don't look at it.
  3. wait for what you think is 30 seconds, and then look at the timer
  4. how many actual seconds elapsed?
The data doesn't need to be particularly high-precision (whole second values are fine). The other data points my friend is looking for are age (in years, again, whole numbers are fine) and gender. You can send me your results by e-mail, (i suspect you can find my address if you're reading this blog). Please put "half a minute for science" in the subject line, and make sure you include: Science thanks you!Tags: science

24 September 2013

Simon Josefsson: BLURB: Software repository metadata convention

As a maintainer of several software packages I often find myself copying text snippets from the README file into different places (savannah, github, freecode, emails, etc). Recently I had a need to generate a list of software packages that included every project s name, brief summary, license and URL. I could have generated that list manually by copying the text from every project s README and COPYING files. However then I would have to maintain my list manually to keep it in sync with all the projects. This easily leads to stale information, so I thought a better approach would be to put the information I needed into each projects source code version control system. The advantage is that the manual work to extract the information may be automated by a script, since the data is in a usable format. I ll explain here how my solution works. To be able to find the information using only the URL to the repository, I needed a filename convention. The filename I chose was BLURB; for the etymology, see Wikipedia s page about Blurb. The data format in the file is similar to normal email headers. An example illustrate the principles well. Below is the BLURB file for one of my projects.
Author: Yubico
Basename: libyubikey
Homepage: http://opensource.yubico.com/yubico-c/
License: BSD-2-Clause
Name: Yubico C low-level Library
Project: yubico-c
Summary: C library for manipulating Yubico YubiKey One-Time Passwords (OTPs)
The format is simple: UTF-8 text with each line starting with a header followed by a colon ( : ), some whitespace, and some content. If a line starts with whitespace, it is a continuation of the previous line s content (trim leading whitespace). The following table describes the fields that I use. I may update this blog post in the future with new fields or improved explanations (for reference, current date is 2013-09-24).
Header Meaning
Project Short identifier for the project (e.g., gcc , emacs )
Name Official name of the project in English
Summary Brief one-line summary of the project s purpose in English
Author Origin of the project
Homepage URL to the project s website
License License keyword, preferrably using one of the SPDX license identifiers
Basename The tarball basename, if different from the project name
Finally some reflection of the solution. After quick design, I thought that I couldn t be the first one with this problem, and I tried to find other similar efforts. I haven t been able to find any standardization effort that have the following properties: The related efforts that I found were SPDX which at first look seemed to offer what I wanted. However on closer examination it failed to deliver on all the requirements above, and appeared to have somewhat different goals. However I found the SPDX license list useful and refer to it. Another effort is Eric S. Raymond s freecode-submit and shipper but its primary focus is to encode information about each release. The design of the BLURB file is clearly influenced by these tools. Another influence has been Debian s specification for machine-readable copyright information. The Free Software Foundation s list of software projects seemed like another candidate, but it doesn t suggest any way to store the information in the upstream project itself. flattr this!

23 September 2013

Gunnar Wolf: This week it was an easy one: On picking free licensing schemes #encirc13

The third lesson of the Arte y cultura en circulaci n: crear y compartir en tiempos digitales course was quite easy, at least for me, as it's one of the topics I've been involved with for a long time: Authors' rights and ways to exercise them. This lesson starts by talking about the paradoxes created in the reality beneath copyright mostly due to the zero-cost-for-perfect-copy reality we live in today, and then goes on to introduce the most widely spread licensing schemes for cultural works nowadays: The Creative Commons licensing schemes. What I felt very interesting is that the lesson tackles the most common issues raised by authors choosing CC licensing: The Non-Commercial and Non-Derivatives restrictions. While authors are usually not very hard to convince about the virtues (and their personal benefit) in CC licensing, it's usually hard for authors to accept and relinquish the "locks" on non-derivability and non-commercial-use. Now, as to the homework: This time, I have to admit it was a no-brainer to me. The homework was to take part of a "Licenciat n": Publish some work under a open or free license (a work of any kind; it can be text, photo, video, etc.; it can be a new or a pre-existing work) and argue as to why did you choose said license. Even the act of writing this blog post means I'm releasing some work. The bottom of my blog reads, All the material found at this site is freely available, and you can use it as you wish, except when the document mentions explicitly different conditions. Yes, this is not a widely known, preexisting licensing scheme, and more or less goes along the lines of CC0 There are some good things I have posted in this blog, some things I am proud about. This post goes more towards the average quality: Not adding anything of great value to the world, just reiterating/reposting what is already said. But I know this blog is syndicated over several different places, and its content might be copied over to other places. I don't need to know or be notified about it. I just care for people to be able to reach back if they want to do it. But, of course, if I'm asked to do a homework, I prefer not to have it so self-referential. What else to license? We are over halfway across the Wiki Loves Monuments contest for 2013. This year I am clearly not as active on it as I was last year, but yesterday I uploaded about 60 photos from our recent trips, from historical monuments in some towns/cities within ~150Km of Mexico City: Puebla, Tlaxcala, Cacaxtla, Toluca, Santiago Tianguistenco. I intend to upload more. Those photos are licensed CC-BY-SA. Why? Mainly, because it is the defaul for the contest. One of the lessons learned working on Debian is that the less the license I choose deviates from what the upstream authors of a larger project prefer, the more useful my work will be. And being Wikimedia a host of many related projects, I prefer to completely abide by their recommendations unless there is a real, strong reason not to do so. Also, I know that at least most the photos I am uploading are not of contest quality (although some are quite nice, but we don't take that long to take a shot, and our camera is probably too basic to get a quality shot, if not by mere chance). I am using the WLM contest as an excuse to categorize and upload my pictures Of course, I'm not including personal photos, but... If I found a building, place or landscape interesting enough to take a photo of, why not make said photo available for whoever needs it, in a canonical, easy to reach media repository (as Wikimedia Commons) is)? And finally, I think it's time to start getting more open and forward-going with a project that I have been giving a lot of work during the past year, a project that has been even eating quite a bit of my Debian time: My upcoming book. While this book is not yet freely licensed (it is freely distributed online, but does not yet have an explicit license, and I mention it on my teaching/project page. Why? Because it still has some figures and data which are not mine, and which I have to re-elaborate to be able to legally license it. But anyway I am writing a book on the subject of Operating Systems, and am basing my teaching on it. The first semester was basically hell for me, as I was working almost full time on it, and needed to allocate some time as well to the rest of my formal work. This second semester has been quite smoother. And there is a very important (to me) initiative to which I (or should I now start saying, we) submitted this work: The LATIn Project: An initiative to collaboratively create quality, freely redistributable text books for the university level, natively in Spanish, for their use in Latin American countries. I was not able to propose this book due to some formalities Projects have to be proposed by professors in participant universities, and UNAM is not one of them. However, I offered this work to people in the Universidad Nacional de Rosario, Argentina, and they managed to push the project forward. Together with people from Universidad Aut noma de Aguascalientes (M xico) and Universidad del Cauca (Colombia), the project was approved by LATIn. And this LATIn project can also be seen as a why do you agree to license your work this way? candidate: I have already written most of what I'd be happy to call a full book. Of course, I do expect my colleagues to chime in with more content, and I expect us to produce a true collaborative project. But as I am not part of the member universities, they will get paid for their contribution And not me. What do I have to gain from this? More than anything else, the circulation of my work. I'm sure that, were I to publish from UNAM, I would have a good projection. I was (am!) thinking of looking for opportunities to present the book to teachers on the subject, as well as to computing engineering/science students, but the most attractive part (for me) for LATIn is that part of the prize will be that the book will be used to base work on for teaching at least during 2014 in the three said universities And of course, my/our work will only start then, as we will have to further circulate the work. Anyway... I expected this post to be small. But as you can see, I am happy with important work perspectives :-)

22 September 2013

Paul Tagliamonte: Musings about Debian and Python

On a regular basis, I find myself the odd-man-out when it comes to talking about how to work with Python on Debian systems. I'm going to write this and post it so that I might be able to point people at my thoughts without having to write the same email in response to each thread that pops up. Turns out I don't fit in with the Debian hardliners (which is to say, the mindset that pip sucks and shouldn't exist), nor do I fit in with the Python hardliners (which is to say apt and dpkg are out of date, and neither have a place on a Development machine). I think our discourse on this topic has become petty and stupid in general. Let's all try to step back and drop a bit of the attitude. pip doesn't suck, and neither does apt. The truth is, both sides are wrong. As with any subject, the real answer here is much more nuanced than either side presents it. I'm going to try and present my opinion on this, in the way that both my Pythonista self and my Debianite self see the issue. Hopefully I can keep this short, to the point, and caked with logic. The case for dpkg (the Debianite in me) In defense of dpkg and apt, imagine having to install python-gnome2 on all your systems when you install. It'd be hell on earth. Imagine having a user try to do this. It's insane to assume that end-users will be using pip for this purpose. pip is fun and all, but it's also installing 100% untrusted code to your system (perhaps as root, if you're using pip with sudo for some reason), and hasn't been reviewed for software freeness, which is something Debian (and Debian users) take seriously. This isn't even to mention the hell that pip wreaks on dpkg controlled files / packages. Try to remember how much of your system running (yes, right now) is running because of Python or Python modules. Try to imagine how much of a pain in the ass it'd be if you couldn't boot into GNOME to use nm-applet to connect to wifi to pip install something. I'm sure even the most extreme pip'er understands the need for Operating System level package management. Debian also has a bigger problem scope - we're not maintaining a library in Debian for kicks, we're maintaining it so that end user applications may use the library. When we update something like Django, we have to make sure that we don't break anything using it (although, to be honest, the fact that we package webapps is an entire rant for later) before we get to update it to the newest release. Hell, with a few coffees, I could automate the process of releasing a .deb with a new upstream release, 100% unattended. I won't, however, since this is an insane idea. Let's go over a brief list of things I do before uploading a new package:
  1. Review the entire codebase for simple mistakes.
  2. Review the entire codebase for license issues.
  3. Review the entire codebase for files without source, and track down (and include source for) any sourceless files (such as pickle files, etc).
  4. Get to know the upstream, get to know open bugs, write something using the lib, in case I need to debug later.
  5. Install the package.
  6. Test the package.
  7. Work out any Debian package issues (this is easy).
Now, a brief list of things I do before I update a package:
  1. Review the changes between the last uploaded version (in diff format, if it's sane, otherwise get the VCS and review), ensure all the above are still OK.
  2. Review for Debian-local issues (such as how it will upgrade, using piuparts, and adequate, etc).
  3. Check to make sure it won't break any reverse dependencies.
  4. Review for bugfixes that I might need to bring back to the stable release.
  5. Figure out if I should (or even can) backport the package, if API is stable.
  6. Review for bugs (upstream or in Debian) that I need to mention in the debian/changelog.
Clearly, this isn't a quick-and-dirty task. It's not a matter of getting a package updated (technically), it's a much more detailed process than that. This is also why Debian is so highly regarded for its technical virtuosity, and why the ISS decided to deploy Debian in space, despite other commercial distros such as Red Hat, or Ubuntu, and community distros, such as Fedora or Arch. It's also not Debian's job to package the world in the archive. This is an insane task, and it's not Debian's place to do it. We introduce libraries as things need them, not because we wrote some new library that someone may find slightly useful at some point in the future. maybe. Upstream developers and language communities (not only Python here) tend to lose sight of why we're doing this in the first place, which is our users. This isn't some sort of technical pissing contest to see who can distribute the software in the best way. Debian-folk always keep end users as our highest priority. I quote the Debian Social Contract, when I say that Our priorities are our users and free software. No one's trying to get developers to use dpkg to create software. In fact, as you'll see below, I actively discourage using system modules for development. The case for pip (the Pythonista in me) In defense of pip, the idea that Debian will keep the latest versions of packages is insane. The idea that we can keep pace with upstream releases is nuts, and the idea that every upstream release on pypi is ready to ship is bananas. b-a-n-a-n-a-annas. As a developer, I don't want to support every release, and I surely don't want other people depending on some random snapshot. Often times, I'll put stuff up on pypi as a preview, or to release often, and solicit feedback without having to give out instructions on using a git checkout (it's also easier to have them try a version from pypi so I can cross-ref the git tag to reproduce issues when they file them) pypi is easy, ubiquitous and works regardless of the platform, which means less of my development time is spent packaging stuff up for platforms I don't really care about (Arch, Fedora, OSX, Windows), even though I value feedback from users on those systems. The effort it takes to release something is limited to python setup.py sdist upload, and it's in a place (and in a shape) that anyone can use it without having 10 sets of platform-local instructions. Even ignoring all the above, when I'm writing a new app or bit of code, I want to be sure I'm targeting the latest version of the code I depend on, so that future changes to API won't hit me as hard. By following along with my dependencies' development, I can be sure that my code breaks early, and breaks in development, not production. Upstreams also tend to not like bug reports against old branches, so ensuring I have the latest code from pypi means I can properly file bugs. Lastly, I prefer virtualenv based setups for development, since I'm usually working on many things at once. This often means version mismatches in libraries, which brings in API changes (another whole rant here as well). I don't want to keep installing and uninstalling packages to switch between the two projects, and using a chroot(8) means a lot of overhead and that it's disconnected from my development environment / filesystem, so I resort to virtualenv to isolate my Development environment. Final notes I don't want to keep arguing about this. Just accept that the world's a big place and that there exist use-cases that both apt and pip need to exist and work in the way they're working now. At the very least, try and understand there exist smart people on both sides, and no one is trying to screw anyone over or keep their own little private club to themselves. Hopefully, going forward, we can make sure that the integration between these two tools gets better, not worse. Help make this dream a reality. Contribute to a productive tone, not a destructive one. In short:

20 September 2013

Enrico Zini: Explanation of umarell

Explanation of umarell
Umarell /uma'r l/ (oo-mah-rell), n; pl. Umarells. People in a community who offer all sorts of comments to those who are trying to get some work done, but who are not doing any work themselves.
Etymology and further details Umarell is a word that entered Italian slang in Bologna and is spreading to nearby towns, occasionally even across Italy. It comes from the Bolognese for "cute/odd little man". "Umarells" are those people, usually retired men, who spend time watching construction works, often holding their hands behind their back, occasionally commenting on what is going on, sometimes trying to tell the workers what to do. It's easy to find examples on the internet; the word was popularised by a blog collecting photos, which has even been published into a book. With some Italian Debian friends, we realised that umarell is the perfect word to describe those people in a community, who offer all sorts of comments to those who are trying to get some work done, but who are not doing any work themselves. I think that it is a word that fits perfectly, and since I'm likely going to use it blissfully anywhere, here is a page that temporarily explains what it means until the Oxford English Dictionary picks it up.

Russell Coker: Qi Phone Charging

I have just bought a wireless phone charging system based on the Qi Inductive Power Standard. I bought a charging device which connects to a standard micro-USB cable and receivers for the Samsung Galaxy Note 2 and Samsung Galaxy S3 phones I own. Both those phones have contacts in the back of their case that are designed for wireless charging so you can install a charging device inside them. The charging devices make the case fit a little tight, and the charging device is stuck to the phone battery with contact adhesive, this makes it impractical to change the battery on a phone with such a device and makes it a little more difficult to swap out a battery case. One nice feature of the Nexus 4 is that it has Qi charging built in, that saved me $19 and was also more convenient. I believe that the main advantage of a wireless charger is to avoid the risk of damage to the phone if it s dropped while connected to a USB charger. This allows the phone to be charged in situations where you might need to quickly or regularly unplug it to go somewhere. One example of how I might use it is when working at an office so I could charge my phone while at my desk and then quickly take it with me if I had to go to a meeting (sadly I have worked in many offices where they have so many meetings). Another example is for sysadmin work where I have to frequently visit devices to fix them. The wireless charging mat that I bought from Kogan connects to a standard micro-USB plug, the good thing about this is that it s easy to find cables and it can take power from any PC. The bad thing about this is that the resistance of the USB cable is a factor that limits the power that a phone can receive, when using wireless charging you have the limit of the cable resistance as well as some power loss from the wireless transmission. After any extended period of charging the charging mat feels warm to the touch and the phone that s been resting on it feels warmer than usual. The warmth is an indication of energy loss which means longer charging times, a longer charging time isn t necessarily a problem as the convenience of wireless charging can allow longer charging times, but if you want to charge your phone in a hurry before you go somewhere then wireless isn t a good choice. In the past I ve discovered that the battery in a Samsung Galaxy S3 can t be charged if the phone is at 46C [1]. 46C might seem extremely hot to people in some parts of the world (EG northern Europe and Canada) but the temperature in even southern parts of mainland Australia can get that hot and it can be hotter in central and northern parts, so phone temperature can be a real issue. Currently my house is at 21C according to a digital thermometer, the Galaxy S3 and the Note 2 are being charged from USB and report temperatures of 27C and 23C respectively. While the thermometer in my house and those in the phones probably aren t really accurate it seems reasonable to assume that the battery of a relatively idle smart-phone that s being charged will be a few degrees warmer than the ambient temperature. The Qi charger makes things a lot worse as it even feels warm to the touch. So maybe a phone on a Qi charger would be 8 degrees warmer than the ambient temperature or more. That implies that in Australian summer weather a Qi charger won t be useful outside or in any building that lacks air-conditioning. So I think we can give up on the idea of using Qi devices to charge phones at a BBQ. Picture of Qi charger on top of Samsung Galaxy Note 2 The final problem I have is that the Qi device is quite small, I took the above picture with my phone face-down because no part of the charger is visible in normal use. With that size I can t just dump a phone like a Note 2 on top of the charging mat and expect it to work. I have to carefully place it so that it balances and so that the wireless receptor inside the phone matches the transmitter in the mat, if the phone isn t placed correctly then the Qi mat won t detect it and won t supply full power to the transmitter. Conclusion I m fairly disappointed in this device. The waste heat makes it unsuitable for Australian summer conditions and slows charging. The difficulty of correctly placing the phone reduces the convenience which is one of the major features. The price was $19 for each charging card for the Note 2 and the S3 and $29 for the charging mat to give a total of $67. I think it s worth the money for me to cover the risk of one of my phones having it s USB port damaged. Using a Qi charger on occasion will decrease the probability of such damage and allow the phone to be used after receiving certain types of damage. The prices of those phones nowadays are $389 for a Galaxy S3 (Kogan price), $250 for a Nexus 4 (when it was on sale in the Google store), and probably about $500 for a Galaxy Note 2 (last time Kogan offered them). So by paying $67 for Qi charging I believe that I m getting some degree of damage insurance for just over $1100 worth of phones. It seems likely that the Nexus 5 will ship with Qi charging support and that the Galaxy Note 3 will also support an optional Qi charging card (which will probably also be $19 or some similar price) so the charging mat should be useful for a long time. While I m disappointed I don t regret buying the device. But I would be hesitant to recommend it to other people and definitely wouldn t recommend it to someone who doesn t have a significant interest and investment in smart phones.

19 September 2013

Daniel Pocock: Install Debian wheezy and jessie directly with btrfs RAID1

Some time ago, I provided an installation report for installing Debian wheezy onto a btrfs RAID1 filesystem. It is not supported directly from the installer partitioning menu partman, but it is not hard to trick the installer to do it, as described in the bug report. I believe this may be a worthy release goal for Debian 8 (jessie), but it is not something I can commit to facilitate myself so I am sharing my experience with it for those who may want to volunteer. Anybody wanting to test it can easily do so with VirtualBox if they don't want to dedicate a real machine to it or if they don't have two real disks in their test machine. My own testing simply involved creating two VirtualBox virtual disks on a single SATA disk. Procedure Here is an abbreviated version of the procedure from the installation report linked above. Run the Debian installer as normal up to the partitioning menu Use manual partition mode Create one big btrfs partition on one HDD (either on a raw partition or on an LV) Designate the partition on one disk as the root FS, designate the partition on the other as unused/unformatted. Continue through the setup, installing to one disk After rebooting into Debian, follow these steps to add the other disk into a RAID1 A variation of this procedure is to use a shell while the installer is running to make the RAID1 during the installation and observe whether /etc/fstab is created correctly. Potential gotchas: is the default fstab sufficient or does it need to be modified after the conversion to RAID1? Does the initframfs need to be regenerated (and potentially modified by hand?) to make it work? Issues to be discussed / resolved Mixing BTRFS filesystems with Logical Volume Management - how many permutations should the installer support? What do people expect/need/require? How to boot if a disk fails? Can grub boot from either? Warning the user when the FS detects instability or failure in either disk

18 September 2013

Russell Coker: Advice for Web Editing

A client has recently asked for my advice on web editing software. There are lots of programs out there for editing web sites and according to a quick Google search there are free Windows programs to do most things that you would want to do. The first thing I m wondering about is whether the best option is to just get a Linux PC for web editing. PCs capable of running Linux are almost free nowadays (any system which is too slow for the last couple of Windows versions will do nicely). While some time will have to be spent in learning a new OS someone who uses Linux for such tasks will be able to use fully-featured programs such as the GIMP which are installed as part of the OS. While it is possible to configure a Windows system to run rsync to copy a development site to the production server and to have all the useful tools installed it s much easier to run a few apt-get or yum commands to install the software and then copy some scripts to the user s home directory. The next issue is whether web editing is the best idea. Sites that are manually edited tend to be very simple, inconsistent, or both. Some sort of CMS seems to be the better option. WordPress is a CMS that I m very familiar with so it s easy for me to install it for a client, while I try and resist the temptation to force my favorite software on clients there is the issue that I can install WordPress quickly which therefore saves money for my client. WordPress is a CMS that supports installing different themes (and has a huge repository of free themes). The content that it manages consists of pages and posts , two arbitrary types of document. Supporting two types of document with a common look and feel and common important data in a side-bar seems to describe the core functionality used by most web sites for small businesses. Does anyone have any other ideas for ways of solving this problem? Note that it should be reasonably easy to use for someone who hasn t had much experience at doing such things, it shouldn t take much sysadmin time to install or cost to run.

Francois Marier: Presenting from a separate user account

While I suspect that professional speakers have separate presentation laptops that they use only to give talks, I don't do this often enough to justify the hassle and cost of a separate machine. However, I do use a separate user account to present from. It allows me to focus on my presentation and not stress out about running into configuration problems or exposing private information. But mostly, I think it's about removing anything that could be distracting for the audience. The great thing of having a separate user for this is that you can do whatever you want in your normal account and still know that the other account is ready to go and configured for presenting on a big screen.

Basics The user account I use when giving talks is called presenter and it has the same password as my main user account, just to keep things simple. However, it doesn't need to belong to any of the UNIX groups that my main user account belongs to. In terms of configuration, it looks like this:
  • power management and screen saver are turned off
  • all sound effects are turned off
  • window manager set to the default one (as opposed to a weird tiling one)
  • desktop notifications are turned off
Of course, this user account only has the software I need while presenting. You won't find an instant messaging, IRC or Twitter client running on there. The desktop only has the icons I need for the presentation: slides and backup videos (in case the network is down and/or prevents me from doing a live demo).

Web browsers While I usually have my presentations in PDF format (for maximum compatibility, you never know when you'll have to borrow someone else's laptop), I use web browsers (different ones to show that my demos work with all of them) all the time for demos. Each browser:
  • clears everything (cookies, history, cache, etc.) at the end of the session
  • has the site I want to demo as the homepage
  • only contains add-ons or extensions I need for the demos
  • has the minimal number of toolbars and doesn't have any bookmarks
  • has search suggestions turned off
  • never asks to remember passwords

Terminal and editors Some of my demos may feature coding demos and running scripts, which is why I have my terminal and editor set to:
  • a large font size
  • a color scheme with lots of contrast
It's all about making sure that the audience can see everything and follow along easily. Also, if you have the sl package installed system-wide, you'll probably want to put the following in your ~/.bashrc:
alias sl="ls"
alias LS="ls"

Rehearsal It's very important to rehearse the whole presentation using this account to make sure that you have everything you need and that you are comfortable with the configuration (for example, the large font size). If you have access to a projector or a digital TV, try connecting your laptop to it. This will ensure that you know how to change the resolution of the external monitor and to turn mirroring ON and OFF ahead of time (especially important if you never use the default window manager or desktop environment). I keep a shortcut to the display settings in the sidebar.

Localization Another thing I like to do is to set my operating system and browser locales to the one where I am giving a talk, assuming that it is a western language I can understand to some extent. It probably doesn't make a big difference, but I think it's a nice touch and a few people have commented on this in the past. My theory is that it might be less distracting to the audience if they are shown the browser UI and menus they see every day. I'd love to have other people's thoughts on this point though. Also, pay attention to the timezone since it could be another source of distraction as audience members try to guess what timezone your computer is set to.

Anything else? If you also use a separate account for your presentations, I'd be curious to know whether there are other things you've customised. If there's anything I missed, please leave a comment!

17 September 2013

Stefano Zacchiroli: sources.debian.net - advanced search and other news

all your ctag (and checksum) are belong to us A few months after the initial announcement, here are some news about the sources.d.n service. I've been late in blogging this, but most of it has been implemented by myself and Matthieu Caneill during DebConf13, which has been a great DebConf, totally exceeding my expectations (and they were already fairly high!). First, you might have noticed some user-visible changes: On the other hand, under the hood: As you usual, your bug reports (and patches!) are more than welcome, just check BUGS before reporting to avoid duplicates.
That's all!

Julien Danjou: Python 3.4 single dispatch, a step into generic functions

I love to say that Python is a nice subset of Lisp, and I discover that it's getting even more true as time passes. Recently, I've stumbled upon the PEP 443 that describes a way to dispatch generic functions, in a way that looks like what CLOS, the Common Lisp Object System, provides. What are generic functions If you come from the Lisp world, this won't be something new to you. The Lisp object system provides a really good way to define and handle method dispatching. It's a base of the Common Lisp object system. For my own pleasure to see Lisp code in a Python post, I'll show you how generic methods work in Lisp first. To begin, let's define a few very simple classes.
(defclass snare-drum ()
())

(defclass cymbal ()
())

(defclass stick ()
())

(defclass brushes ()
())

This defines a few classes: snare-drum, symbal, stick and brushes, without any parent class nor attribute. These classes compose a drum kit, and we can combine them to play sound. So we define a play method that takes two arguments, and returns a sound (as a string).
(defgeneric play (instrument accessory)
(:documentation "Play sound with instrument and accessory."))

This only defines a generic method: it has no body, and cannot be called with any instance yet. At this stage, we only inform the object system that the method is generic and can be then implemented with various type of arguments. We'll start by implementing versions of this method that knows how to play with the snare-drum.
(defmethod play ((instrument snare-drum) (accessory stick))
"POC!")

(defmethod play ((instrument snare-drum) (accessory brushes))
"SHHHH!")

Now we just defined concrete methods with code. They also takes two arguments: instrument which is an instance of snare-drum and accessory that is an instance of stick or brushes. At this stage, you should note the first difference with object system as built into language like Python: the method isn't tied to any class in particular. The methods are generic, and any class can implement them, or not. Let's try it.
* (play (make-instance 'snare-drum) (make-instance 'stick))
"POC!"

* (play (make-instance 'snare-drum) (make-instance 'brushes))
"SHHHH!"

* (play (make-instance 'cymbal) (make-instance 'stick))
debugger invoked on a SIMPLE-ERROR in thread
#<THREAD "main thread" RUNNING 1002ADAF23 >:
There is no applicable method for the generic function
#<STANDARD-GENERIC-FUNCTION PLAY (2)>
when called with arguments
(#<CYMBAL 1002B801D3 > #<STICK 1002B82763 >).

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
0: [RETRY] Retry calling the generic function.
1: [ABORT] Exit debugger, returning to top level.

((:METHOD NO-APPLICABLE-METHOD (T)) #<STANDARD-GENERIC-FUNCTION PLAY (2)> #<CYMBAL 1002B801D3 > #<STICK 1002B82763 >) [fast-method]

As you see, the function called depends on the class of the arguments. The object systems dispatch the function calls to the right function for us, depending on the arguments classes. If we call play with instances that are not know to the object system, an error will be thrown. Inheritance is also supported and the equivalent (but more powerful and less error prone) equivalent of Python's super() is available via (call-next-method).
(defclass snare-drum () ())
(defclass cymbal () ())

(defclass accessory () ())
(defclass stick (accessory) ())
(defclass brushes (accessory) ())

(defmethod play ((c cymbal) (a accessory))
"BIIING!")

(defmethod play ((c cymbal) (b brushes))
(concatenate 'string "SSHHHH!" (call-next-method)))

In this example, we define the stick and brushes classes as subclass of the accessory class. The play method defined will return the sound BIIING! regardless of the accessory instance that is used to play the cymbal. Except in the case where it's a brushes instance; only the most precise method is always called. The (call-next-method) function is used to call the closest parent method, in this case that would be the method returning _"BIIING!".
* (play (make-instance 'cymbal) (make-instance 'stick))
"BIIING!"

* (play (make-instance 'cymbal) (make-instance 'brushes))
"SSHHHH!BIIING!"

Note that CLOS is also able to dispatch on object instances themself by using the eql specializer. But if you're really curious about all features CLOS provides, I suggest you read the brief guide to CLOS by Jeff Dalton as a starter. Python implementation Python implements a simpler equivalence of this workflow with the singledispatch function. It will be provided with Python 3.4 as part of the functools module. Here's a rough equivalence of the above Lisp program.
import functools

class SnareDrum(object): pass
class Cymbal(object): pass
class Stick(object): pass
class Brushes(object): pass

@functools.singledispatch
def play(instrument, accessory):
raise NotImplementedError("Cannot play these")

@play.register(SnareDrum)
def _(instrument, accessory):
if isinstance(accessory, Stick):
return "POC!"
if isinstance(accessory, Brushes):
return "SHHHH!"
raise NotImplementedError("Cannot play these")

We define our four classes, and a base play function that raises NotImplementedError, indicating that by default we don't know what to do. We can then write specialized version of this function with a first instrument, the SnareDrum. We then check for the accessory type that we get, and return the appropriate sound or raise NotImplementedError again if we don't know what to do with it. If we run it, it works as expected:
>>> play(SnareDrum(), Stick())
'POC!'
>>> play(SnareDrum(), Brushes())
'SHHHH!'
>>> play(Cymbal(), Brushes())
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/jd/Source/cpython/Lib/functools.py", line 562, in wrapper
return dispatch(args[0].__class__)(*args, **kw)
File "/home/jd/sd.py", line 10, in play
raise NotImplementedError("Cannot play these")
NotImplementedError: Cannot play these
>>> play(SnareDrum(), Cymbal())
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/jd/Source/cpython/Lib/functools.py", line 562, in wrapper
return dispatch(args[0].__class__)(*args, **kw)
File "/home/jd/sd.py", line 18, in _
raise NotImplementedError("Cannot play these")
NotImplementedError: Cannot play these

The singledispatch module looks through the classes of the first argument passed to the play function, and calls the right version of it. The first defined version of the play function is always run for the object class, so if our instrument is a class that we did not register for, this base function will be called. For whose eager to try and use it, the singledispatch function is provided Python 2.6 to 3.3 through the Python Package Index. Limitations First, as you noticed in the Lisp version, CLOS provides a multiple dispatcher that can dispatch on the type of any of the argument defined in the method prototype, not only the first one. Unfortunately, Python dispatcher is named singledispatch for this good reason: it only knows to dispatch on the first argument. Guido van Rossum wrote a short article about the subject that he called multimethod a few years ago. Then, there's no way to call the parent function directly. There's no equivalent of the (call-next-method) from Lisp nor the super() function that allows to do that in Python class system. This means you will have to use various trick to bypass this limitation. So while I am really glad that Python is going toward that direction, as it's a really powerful way to enhance an object system, it really lacks a lot of more advanced features that CLOS provides out of the box. Though, improving this could be an interesting challenge. Especially to bring more CLOS power to Hy. :-)
The Hacker Guide to Python
A book I'm writing that will be launched soon, talking about designing Python applications, state of the art, and various Python tips. If you want to be the first to hear about the launch, subscribe now.

Cyril Brulebois: Fixing bugs

It s a somewhat strange feeling to spend time fixing things that broke instead of implementing new things, but it s not like I m a creative guy anyway For those last two points, the long term plan is: Hopefully getting this done this week (famous last words, eh?).

16 September 2013

Gunnar Wolf: My favorite (or rather, one among my favorite) non-original work Leo Masliah #encirc13

It seems I'm catching up with the pace of this course I'm following and that is compelling me to go back to posting on my blog, Arte y cultura en circulaci n: crear y compartir en tiempos digitales . This week's lesson is (again, in Spanish) Las fronteras del remix (the boundaries of remixes). An interesting text, open to everybody (regardless of whether you are signed up for the course or, I hope, whether time has passed since the course took place). And this week's homework is to find "our favorite" non-original work (I picked one among my favorite works And, yes, this is partly because I am part of the "club" of deniers of true originality: We cannot create anything without being part of a surrounding culture, without a common heritage and language with which we speak to our audience) and to find something about it, anything considered important or significative as to its antecedents. What do I like about this work, what grabs my attention. Do I consider it to be a true new creative work? Why? I am taking as an example Leo Masliah, an Uruguayan writer and musician (writer and interpreter). I have followed and enjoyed Masliah's work since 1996, and although by far I'm most familiar with his musical works, I have two books (a novel and a series of short stories). Among his facets, I most enjoy the acid, nihilistic/dadaistic streaks. I chose three of his songs to talk about I am linking to anonline resource where possible, but uploading the three songs to this blog to make his work better known, so that people understand what I talk about, and with my best intentions. Of course, if there is any request to remove the material, I will do it right away. I hope this can be seen as fair/academic use, although this blog is somewhat widely read.
La recuperaci n del unicornio
This song was in the first Masliah cassette I came across, Although musically it is an original work, the lyrics are a clear, almost line-by-line reply to the ever-repeated Unicornio song, by Silvio Rodr guez. This song (which I'm sure that every Spanish speaker reading this lines knows, like it or not It defines for me a good deal of Rodr guez hyper-sweetness and clicheness) has been analyzed over and over looking for a meaning. Silvio recorded this song in 1981, and by 1987 Masliah published this answer, mocking each of the lines.
So, this song can be seen as an original creation, as it contains no literal copy neither of the music nor of the lyrics of the original, but it cannot be understood without being familiar with Silvio's lost unicornio. It would just be an almost-dadaistic rant. But every person that has tasted Silvio Rodr guez cloying song will surely laugh with this one.
No necesitamos otro h roe Balderrama
I find this to be a very unique piece. It bonds together Argentinian folklore and USA pop.
Masliah sings the famous Argentinian song Zamba de Balderrama, (Castilla / Leguizam n), a song lamenting that the very popular bar and artist stage Balderrama, in Salta (North-Western corner of Argentina), seemed to be on the brink of closing. Of course, when Mart n, Constanza, Regina and me went to Balderrama in July 2010, the danger of closing this place had long been averted. And basically every Argentinian knows this song by heart.
The interesting part is that Masliah sings this song (as he presents it as the closing piece for one of his concerts) being short on time, and decides to present two acts together: Zamba de Balderrama and We don't need another hero, by Tina Turner, from the Mad Max soundtrack. So, of course, even if it's obvious that Masliah had to stretch bits to make them fit together, he achieved a very funny, interesting and unique blend of two completely unrelated works. He derives from one as well as from the other, but creates something unique and new.
Donna Lee
I was thinking what to write for this assignment , and had already chosen the two other songs. Yesterday, we were visiting our friends Octavio and Claudia, in Guanajuato, and I heard for the first time the original(?) version of Donna Lee, by Miles Davis (although often credited to Charlie Parker). That led me to remember Masliah's interpretation, in his Cl sicos album. This album is basically made up with similar excercises: Taking an instrumental piece, with Masliah singing over it. Some of the lyrics follow the story (i.e. the children stories), others just talk nonsense to illustrate a point (i.e. "La voz del medio", "the middle voice") follows the non-protagonist score trying not to grab much attention to the lyrics but to highlight the often ignored melody)... Donna Lee is just a fun excercise on following the melody asking what was in the head of the author that led him to invent such a strange, hard music.
Masliah is a great music performer, although often it seems he tries to hide it (i.e. by abusing the dissonances, ex-profeso singing off-key, etc), and a very funny and crazy author. Most of his works have a deep satirical tone, and it's common to find either simple winks or complete "borrowings" in a clear remix fashion, but nobody will doubt on the originality of his works.
AttachmentSize
07-Donna Lee.MP31.79 MB
16 No necesitamos otro h roe - Balderrama.mp33.49 MB
Leo Masl ah-La Recuperaci n Del Unicornio.mp31.87 MB

Debian Med

DebConf 13 report (by Andreas Tille) General impression unofficial  Scenic Hacklab I'm beginning my DebConf report in an unofficial "Scenic Hacklab" right at the edge of the lake in Yverdon. This is the right place to memorise the last days. When I started from this place cycling to Le Camp 12 days ago I was full of great expectations and what should I say - the reality has even beaten these. Once it comes about comparing DebConfs even if it is an unfair comparison due all the differences my secret long term favourite was Helsinki very closely followed by Argentina and also very closely followed by all the other great DebConfs I joined (and I joined all in Europe). Would Le Camp be able to beat it? The short answer is: Yes, it is now my favourite DebConf while I think I do not suffer from the last-Debconf-was-the-best-DebConf-syndrome (and I realised there are others thinking the same). As you might probably know I'm a bit addicted to swimming. While Helsinki had admittedly the better conditions I was at least able to fix the distance issue using my bicycle. (Hey, those Le Camp photographers did a great job in hiding the fact that you can not actually touch the lake right from the meadow of Le Camp.) Being able to have my bicycle at DebConf scored some extra points. However, the really great view of the lake, the inspiring "Scenic Hacklab" which was my favourite place has bumped DebConf13 at first place in my personal ranking. So it comes quite natural to say: "Kudos to the great organisation team!" They did a Swiss-like precise work and perfectly succeeded in hiding any problems (I assume there were some as always) from the attendees so everything went smooth, nice and shiny for the attendees. The local team was even precise in setting up great weather conditions for DebConf. sunrise over  the lake While saying thanks to the local team I would like to also explicitly thank Luca Capello who has quite some share that this DebConf was possible at all (while I have to decrease my DebConf score one point because he was not really there - Luca to bad that you were not able to come full time!) Also thanks to Gunnar and Gannef who helped remotely (another score down because I were missing them this year as well). Even if it was my favourite DebConf I was not able to work down my todo list fully (which was not only uploading one package per day which I at least statistically fullfilled). But that's probably a general feature of todo lists anyway. One item was definitely done: Doing my daily swimming BoF. I actually was able to do the other parts of the triathlon which was skipped by Christian and have done in summary about 150km cycling with 3500m elevation and estimated 7-8km swimming (0m elevation ;-)). Considering the great view at sunrise over the lake I was not hating my "Senile bed escape" disease too much (I was every day waking up at sunset) - it was simply a great experience. I will never forget seeing water drips glimmering like gold inside the morning sun while seeing the Alps panorama in the distant. I hope I was able to help all interested swimmers with the DebConf Beach Map which was just a by-product of my activities in DebCamp. Speaking about OSM: I was astonished that the area was way less covered than I expected. Thanks to several DebConf attendees the situation became better and the map does not only show random trees in the wild but also the tracks leading to these. (Remark: It was no DebConf attendee who is responsible for plastering the map with single trees.) While I had my mapping focus basically close to the edge of the lake I was also able to even map my very own street. :-) I clearly remember one specific mapping tour when I was invited by the DPL: He convinced me to join him on a bicycle tour and since I was afraid to get fired I joined him instead to keep on hacking. Also Sorina was brave enough to join us on the tour and she did quite well. (Sorina, do you remember the agreement about your work on the installer? ;-)) Lucas described the tour as: going uphill on only asphalted roads. Sorina and me were witnessing the mighty DPL powers when we left the wood around Le Camp to reach the described road: The asphalt was just put onto the road - no doubt that it was done on the immediate demand of mighty DPL. :-) DebCamp time was flying like nose dive and a lot of known (and unknown) faces arrived at Le Camp. What I really liked a lot this year was that several really young children has pulled down the average age of DebConf attendees. I clearly remember all the discussion one year ago what to do about children. As always the issue was solved in a typical Debian way: Just do it and bring your children - they had obviously a great time as well. I think the youngest child was 2 months and the oldest "child" above 20. ;-) Actually Baptiste Perrier did great in making the C&W party a success and had obviously a nice time. (I wished my son would have been able to come as well but he needs to write his bachelor s thesis in physics. :-() It was nice to see the kids using all playing facilities and communicating with geeks. Also I would like to point out that even the very young attendees had their share at the success of DebConf: Just think of the three "bell ringing assistants" who helped me ringing the bells for lunch and dinner. I've got this cool job from Didier in the beginning of DebCamp. I must say having some real bells ringing is by far nicer than just the "lunch / dinner starts in 10 minutes" from IRC bot. The only thing I did not understand was that people did not considered ringing the bells at 8:00 for breakfast as a good idea. Regarding the food in general I would also like to send kudos to the kitchen: It was tasty, freshly prepared, regional food with a good change rate. I really liked this. Extra points for having the chance to sit outside when eating. Talks But lets have a look into the conference programme. I'd really recommend watching the videos of the talks Bits from the DPL (video) and Debian Cosmology (video). I considered both talks as entertaining and interesting. I also really hope that the effort Enrico Zini started in Debian Contributors (video) will be successful. I had some talks and BoFs myself starting with Why running a Blend (video) and I admit that (as usual) the number of attendees was quite low even if I think there is some proof (see below) that it is interesting for way more people who should consider working more "blendish" in their team. Do you know how to recruit one developer per year and relax the man power problem in your team? Feel free to watch the video. We have confirmation that ten DDs of our team have considered to join Debian only because Debian Med exists. Admittedly biology and medicine are really leaf topics inside the Debian universe. So if even this topic that has a very tiny share of the Debian users is able to attract this level of attention - how many more people could we win for multimedia, games, GIS and others? So if you feel you are quite overworked with your packaging and you have no time this is most probably wrong. The amount of time is basically a matter of priorities you set for your tasks. Try to put some higher priority onto using the just existing Blends tools I explained in my talk to attract more users and developers to your team and by doing so spread the workload over more people. It works, the prove was given in my main talk. So before you start working on a specific package you should wonder who else could have an even stronger interest to get this work done and provide him with some additional motivation and help to get the common goal done. The interesting thing is that my BoF about How to attract new developers for your team (video) - which was a simple report about some by-product of the Blends work - made it into the main talk room and got way more attention. For me this is the proof that the Blends concept itself is probably badly perceived as something like "a few outsiders are doing damn specific stuff which is not really interesting for anybody else" instead of what is really is: Smoothing the way from specific upstream applications to the end user via Debian. Once you see the video of this BoF you can observe how my friend Asheesh Laroia became more and more excited about the Blends concept and admitted what I said above: We should have more Blends for different fields. Funnily enough Asheesh asked me in his excitement to talk more about Blends. This would have been a really good suggestion ten years ago. At DebConf 3 in Oslo I had my very first talk about Blends (at this time under the name "Debian Internal Projects"). I continuously kept on talking about this (MiniDebConf Peking 2005, DebConf 5, Helsinki (video), DebConf 7, Edinburgh (video), DebConf 8, Mar del Plata (video), DebConf 9, C ceres (video), MiniDebConf Berlin 2010 (video in German), MiniDebConf Paris 2010 (not video recorded), DebConf 11, Banja Luka (video) ... and these are only (Mini)DebConfs my talks page is full of this topic) and every new year I try different ways to communicate the idea to my fellow Debianistas. I'm wondering how I could invent a title + abstract avoiding the term Blends, put "Git", "release" and "systemd versus upstart" in and being able to inform about Blends reasonably by not becoming to off topic with the abstract. I also registered the Debian Science round table. I admit we were lacking some input from remote via IRC which used to be quite helpful in the past. The attendees agreed upon the handling of citations in debian/upstream files which was invented by Debian Med team to create even stronger bounds to our upstream developers by giving their work extra reward and providing users with even better documentation (see my summary in Wiki). As usual I suggested to create some Debian Science offsprings like "Debian Astronomy", "Debian Electronics", "Debian Mathematics", "Debian Physics" etc. who could perfectly leave the Debian Science umbrella to get a more fine grained structure and a more focused team to enhance the contact to our users. Unfortunately there is nobody who volunteers to take over the lead for such Blends. I have given a short summary about this BoF on the Debian Science mailing list. In the Debian Med meeting I have given some status report. No other long term team members were attending DebConf and so I gave some kind of introduction for newcomers and interested people. I touched also the DebiChem topic which maintains some packages that are used by biologists frequently and so we have a good connection to this team. Finally I had registered three BoFs in Blends I'm actually not (or not yet) active part of. My motivation was to turn the ideas I have explained in my main talk into specific application inside these teams and helping them to implement the Blends framework. In the first BoF about Debian GIS I have shown the usual team metrics graphs to demonstrate, that the one packaging team Pkg-OSM is in danger to become MIA. There are only three persons doing actual uploads. Two of them were at DebConf but did not joined the BoF because they do not consider their contribution to Pkg-OSM as a major part of their general Debian work. I will contact the main contributor David Paleino about his opinion to move the packages step by step into maintenance of Debian GIS packaging team to try to overcome the split of two teams that are sharing a good amount of interest. At least if I might become an Uploader for one of the packages currently maintained by Pkg-OSM I will move this to pkg-grass-devel (which is the name of the packaging team of Debian GIS for historical reasons). The attendees of the BoF have considered this plan as sensible. Moreover I talked about my experiences with OSGeo Live - an Ubuntu derivative that tries to provide a full tool chain to work on GIS and OSM problems ... basically the same goal as Debian GIS has just provided by the OSGeo project. I'm lurking on OSGeo mailing list when I asked explicitly I've got the answer that they are working together with Debian GIS and are using common repository (which is IMHO the optimal way of cooperation). However, it seems that several protagonists of OSGeo Live are underestimating the resources provided by Debian. For instance there was a question about Java packaging issues but people were not aware about the existence of the debian-java mailing list. I was able to give an example how the Debian Med team managed to strengthen its ties to BioLinux that is also an Ubuntu derivative for biologists. At our first Debian Med sprint in 2011 we invited developers from BioLinux and reached a state where they are using the very same VCS on Alioth where we are maintaining our packages. At DebConf I was able to upload two packages where BioLinux developers did certain changes for enhancing the user experience. My "work" was just bumping the version number in changelog and so we did profit from the work of the BioLinux developers as well as they are profiting from our work. I plan to dive a bit more into Debian GIS and try to strengthen the connection to OSGeo Live a bit. The next BoF was the Debian Multimedia meeting. It was nice that the current leader of Ubuntu Studio Kaj Ailomaa joined the meeting. When I was explaining my ideas about cooperation with derivatives I repeated my detailed explanation about the relation with BioLinux. It seems every topic you could cover inside Debian has its related derivative. So to me it seems to be quite natural to work together with the developers of the derivative to join forces. I actually consider a Blend a derivative done the right way = inside Debian. The final work for the derivers that might be left for them is doing some shiny customising of backgrounds or something like this - but all the hard work could and should be done in common with the relevant Debian team. My dream is to raise such relevant teams inside Debian ... the Blends. Finally the last BoF of this series was the Debian Games meeting. As always I presented the team metrics graphs and the Debian Games team members who attended the BoF were quite interested. So it seems to be some unknown fact that team metrics are done for several teams in side Debian and so I repeat the link to it for those who are not yet aware of it. As a result of the BoF Debian Games team members agreed to put some more effort into maintaining their Blends tasks. Moreover Miriam Ruiz wants to put some effort into reviving Debian Jr. Regarding Debian Jr. there was an interesting talk about DouDouLinux - in case you might want to watch the video I'd recommend skipping the first 30min and rather watch the nice live demo. There was also an ad hoc BoF about Debian Jr scheduled to bring together all people interested into this cute project and Per Anderson volunteered to take over the lead. I have given a summary about this specific BoF at the Debian Jr list. For some other talks that I'd regard as remarkable for some reasons: I'd regard the talk "Debian-LAN" by Andreas Mundt as some hidden pearl because it did not got a lot of attention but after having seen the video I was quite impressed - specifically because it is also relevant for the Blends topic. Memories I also liked "Paths into Debian" by Moray Allan (and I was only able to enjoy the latter talks thanks to the great work of the video team!) because it also scratched the same topic I was concerned about in my mentoring talk. Related to this was in my opinion also "Women in Debian 2013" were we tried to find out reasons for the lack of woman compared to other projects and how to overcome this issue. Geert hovering  over the grass Besides the talks I will probably never forget two specific moments that make DebConf so special. One of these moments is recorded on an image that clearly needs no words - just see Geert hovering over the grass. Another strong moment in my personal record was in the DebConf Newbies BoF "First time at DebConf" that unfortunately was not recorded but at least for this statement it would have been very great if we would have some reference better than personal memory. Aarsh Shah a GSoC student from India suddenly raised up and said: "Four months ago I was not even aware that Free Software exists. Now I'm here with so many people who are totally equal. If I will tell my mother at home that I was standing in the same queue where the Debian Project Leader was queuing up for food she will never believe me." He was totally excited about things we are regarding as normal. IMHO we should memorise moments like this that might be part of the key to success in cultures, where Debian is widely unknown and very rarely in use. Amongst these not scheduled great moments the scheduled day trip was also a great thing. I had a really hard time to decide what tour I might join but ended up in the "long distance walking (or should I say running) group". Inspired by the "running Bubulle" who was flashing between the walking groups we went uphill with 5.4km/h which was a nice exercise. Our destination the large cliff was an exciting landscape and I guess we all enjoyed the dinner organised by the "Trout cabal". ;-) say goodby to  friends So I had a hard time to leave Le Camp and tried hard to make sure my memories will remain as long as possible. Keeping some signs attached to my bicycle, conserving the "Scenic Hacklab" sign for my private "scenic hacklab @ home" was one part. I also have cut some branches of the Buxus sempervirens in Le Camp and have put them in my garden at home (where I create some hedgerow from places where I spent some great time). These will probably build a great part of the hedgerow ... Thanks for reading this longish report. Looking forward to see you all in Germany 2015 (or earlier) Andreas. Scenic Hacklab  @ home

15 September 2013

Robert Millan: Rooting the LG Optimus L3 (and just about any Android model, really)

I recently purchased an LG Optimus L3 ( e400 ) mobile phone. I ve to admit it would be a perfectly fine purchase if it wasn t for the huge amount of time I had to invest in order for this thing to recognize me as its master. Even though I wanted to install CyanogenMod in it, the device blocked my attempts to install it through ROM Manager. Yes, for some awkward reason LG kept on thinking they still owned the device even after they sold it to me. Anyway, as none of the rooting instructions for LG Optimus L3 I found on the net worked for me, I figured I should try with the recently-discovered master key vulnerability. A bit of research shows there s very extensive documentation on this hole and how to exploit it, as well as proof-of-concept exploits. But unfortunately, I haven t been able to find any complete solution to implement this in easy steps. On the soulders of giants After running through the whole manual setup of this exploit (and succesfully rooting my LG Optimus L3), I figured it would be useful if I put the pieces together into a unified script. So here it is, an exploit for the Android master key vulnerability which will give you root access to almost every Android device in existance: https://github.com/robertmillan/mkbreak Enjoy. Oh and btw: fuck you LG.

13 September 2013

Daniel Pocock: Calendar and Contact data with free software in the Smartphone era

Since the rise of smartphones, first Blackberry, then iPhone and now Android, the world at large has had a convenient option to fall back on for management of contact and calendar data. The data itself seems somewhat trivial: many of us software developers have worked with a plethora of obscenely more obscure schemas. It is unlikely that most people would ever have to perform an operation on their address book that requires a statistical toolkit like the R project or any of the other advanced tools we now have for data processing. In terms of data, addresses and phone numbers can appear quite boring. So why hasn't the free software community mastered it and cloud providers are currently running rampant hoovering up the data of billions of users? Ruling out LDAP One problem that people have faced is the existence of different standards. LDAP has quite a high profile and appears to be supported by default in many desktop applications. For this reason, it tends to grab people's attention but after a close look, many people find it is not the right solution. LDAP tends to work well for organisations where the data is centrally managed and in situations where fine-grained access control is not required. LDAP servers often need a capable UNIX administer to manage effectively. To top it off, LDAP itself does not provide an effective solution for two-way synchronization of data with remote and mobile users. The emergence of SyncML, CalDAV, GroupDAV and CardDAV Addressing this final problem (two-way mobile/portable device sync) has brought on the development of further standards. Initially, SyncML (now known as Open Mobile Alliance Data Synchronization and Device Management) grabbed significant attention, partly because it had been included in some of the first generation of smartphones from once-prominent vendors like Nokia. Open source server solutions for SyncML did not gain traction though. The most prominent is Funambol, however, it is not packaged in any major Linux distribution and it requires some basic Java knowledge to maintain it effectively. Like LDAP it appears to be most comfortable in enterprise use cases and doesn't appeal to the people who run a private mail and web server. SyncML has further suffered with the lack of support in more recent generations of smartphones. WebDAV was formalised in 1999 and there are now various derivative standards such as CalDAV and CardDAV which use WebDAV as a foundation. However, standards didn't arrive at this place directly: CalDAV only appeared as RFC 4791 in 2007 and CardDAV as RFC 6352 in 2011. In the meantime, some vendors experiemented with an alternative called GroupDAV. GroupDAV is largely obsolete now and GroupDAV v2 is a subset of CalDAV and CardDAV. Finally gaining traction The good news is, CardDAV and CalDAV are gaining traction, in no small part due to support from Apple and the highly proprietary iPhone. Some free software enthusiasts may find that surprising. It appears to be a strategic move from Apple, using open standards to compete with the dominance of Microsoft Exchange in large corporate networks. Both protocols are supported natively in iPhones and Mac OS X. More exciting, Apple releases their Contacts Server and Calendar Server as open source software, making it easier to look under the hood and observe any deviations from the standards. Apple's adoption of CardDAV and CalDAV has been accompanied by a similar effort in free software, however, support is more patchy. The Mozilla Lightning calendar plug-in for Thunderbird (known as the iceowl-extension plugin for icedove on Debian) has supported CalDAV for some time. In contrast, Thunderbird's address book lacks native support for CardDAV and has other limitations (discussed in detail below). Limited CardDAV support in Thunderbird can be achieved using the third-party SOGo Connector, which is not just for ScalableOGo server. The Evolution PIM appears to support both CardDAV and CalDAV relatively smoothly and appears to be more functional and easier to get started with. Free software servers are also emerging. DAViCal, despite the name, supports both CardDAV and CalDAV. It is a good solution for people who have an existing mail server and don't want to transition to an all-in-one groupware suite. Packages available in Debian make it easy to deploy and get started. It is a PHP solution, using a PostgreSQL database underneath. For people who do want a groupware suite, CardDAV and CalDAV are supported in products like ScalableOGo and Zimbra. For people who don't want a server at all and just want to sync between a desktop and a mobile device, there are options like Calypso. Mobile support: the missing link A number of people have blogged about using the Android apps CardDAV-Sync and CalDAV-Sync to complete the picture. I've tested these myself and verified that they work. However, there is one vital thing missing: the source code. Nobody knows what is inside these apps except the developer. That makes it impossible for other developers to troubleshoot them and improve them and it also makes it impossible to be certain that they do not leak information. An alternative is the aCal app for Android. Despite the name, aCal can synchronize the address book as well as the calendar. However, in my tests against DAViCal, I found that the addressbook can only be synced once and that on subsequent syncs, it fails to discover any new server-side contacts. aCal source code is available on gitorious.
aCal appears to be a compelling solution for Android users, hopefully the contact sync will be fixed soon. It only syncs once after installation and then fails to detect any new contacts. Thunderbird's limitations It has already been mentioned that the Thunderbird address book can be synchronized to a CardDAV server by adding the SOGo Connector plugin. However, this is not a perfect solution. The plugin itself is fine: the SOGo web site describes the connector (as opposed to the SOGo Integrator plugin) as a portable solution: in other words, it is vendor neutral, compatible with any standards-compliant server. The first limitation is that it is necessary to duplicate the setup process for both the calendar sync and the address book sync. This is just a question of convenience.
The SOGo Connector plugin configuration window is very trivial. I recommend using read-only mode to avoid the problems with multiple email addresses or telephone numbers. More serious limitations exist in the address book itself: if the CardDAV server has more than 2 email addresses, they will not appear in the Thunderbird address book. Changing an email address on the client side will result in loss of those additional email addresses on the server-side. The Mozilla team initially committed to rewrite the address book from the ground up but it is not clear whether that work is still in progress. DAViCal confusion I had been using DAViCal for quite some time as a CalDAV server before I recently decided to try and use it for CardDAV as well. As a calendar server, it had been working fine. I have a small number of users with some private calendars and also some shared calendars. When I installed the SOGo Connector plugin and went to setup the client-side configuration, it asked me for the server URL. Having used CalDAV already, I simply tried copying the existing CalDAV URL, which is of the form https://myserver.example.org/davical/caldav.php/daniel/home The URL was accepted and I could create address book entries on the client side. No errors appeared. I then tried setting up the same URL as an address book in Evolution. This time, I found I was able to create contacts and sync them to the server and access them from another copy of Evolution. It appeared DAViCal was working fine and I felt that Thunderbird or the SOGo Connector was somehow broken, because the Evolution clients were syncing but Thunderbird was not. The lack of any errors from the Thunderbird GUI further undermined my confidence in the SOGo Connector. Nonetheless, I decided to dig a little deeper, looking through the DAViCal source code. This brought me to the realisation that each URL could be flagged as either a calendar resource or an address book resource. This had not been obvious to me before. Evolution had effectively been storing the contact entries into a calendar URL and DAViCal had been happily accepting them. SOGo Connector, querying the URL, appears to have received both calendar and contact records from DAViCal and given up.
Here is where I configured the extra resource for an address book store under my user account in DAViCal In the DAViCal web management console, I created an extra resource for my user ID and set the appropriate checkbox to mark the resource as an address book. Then I put this resource URL into all the clients and found that they were all able to sync with each other. DAViCal's maintainer has explained that this is a limitation in the CardDAV/CalDAV protocols: technically, it is valid for the client to store the wrong type of objects in each URL. Clients need to be more resilient when they stumble across objects they don't expect in a particular resource. Conclusion A complete free software based contact-management solution can be easily deployed using any of the servers mentioned above, particularly if Evolution is the preferred client software. Using Thunderbird as a client, it can also work, but attention is needed to avoid data loss on sync. Thunderbird could also be used in a read-only mode to access address books maintained with Evolution. Mobile support is still patchy on Android. The closed source solution (CardDAV-Sync and CalDAV-Sync) appears to work and a promising open source close, aCal, appears to be "nearly there". Some people would obviously prefer to use a standalone contact/calendar server, while others may prefer an all-in-one groupware suite. Both approaches appear to be feasible, but the standalone contact/calendar server appears to offer a more compelling way to start quickly and have minimal administrative overhead, particularly due to the fact that DAViCal is available in a supported package.
This is the contact server configuration window in Evolution. It offers slightly more options than SOGo Connector in Thunderbird and appears to be a more finished solution overall.

MJ Ray: Upgrading to Debian 7 wheezy

So I have upgraded my main workstation at last, but there are a few things I wanted to figure out. Some of these I found an answer to, but others I haven t and some answers open more questions: Where did debian-menu.menu go and why doesn t lxlauncher have the Debian menu by default anyway? Answer: It seems this is a combination of debian bug 333848 and bug 722563 which I reported yesterday in that lxlauncher doesn t use the debian menus. Workaround for now: install menu-xdg and hack the lxlauncher menu file. Why don t my xterm shells load .profile any more? Did I bodge that before without making a note? How do I stop kernel or initrd or whatever it is configuring the network with the dhcp settings at boot time instead of the better wicd ones that are available once the system is up? Continuing with networking, how did network-manager (which doesn t cope with my network configuration) get installed again? Answer: debian bug 645656 explains that debian is simply following a silly decision taken upstream and refers to attempts to make network-manager optional as the Crusade . Workaround: remove gnome and install its dependencies like gnome-core directly instead. Drawback: any new dependencies of gnome will have to be installed manually. Why is the audio capture volume at 10% by default and what s the best way to change that? I suspect this might be 682731 but that bug is untouched in over a year. I m tempted to remove pulseaudio, but gnome-core Depends pulseaudio so this is yet more hardware-breaking caused by gnome dependency changes and the only way out of this one would be to remove gnome-core and install its dependencies. Or maybe I should just give up and finally remove gnome because its packages have jumped the shark. I installed gnome to make the system easier to use and it s broken it in at least two ways now. One question that makes me hesitate is: why is gdm3 faster to start than lightdm?

12 September 2013

Russ Allbery: AFS::PAG 1.00

One of the very long-standing problems with AFS is that it doesn't have a stable library interface or API. The situation with shared libraries is even worse. Despite that, there is a native XS AFS Perl module that tries to provide a native Perl interface to the various AFS libraries, despite all of their quirks. We've used that off and on for various things over the years. Unfortunately, the historic AFS code used an LWP (lightweight threading) implementation that relied on hairy C internals, and when Perl switched over to being threaded with POSIX pthreads by default, the loadable module started having trouble. Various people managed to keep it limping along through Debian's squeeze release, but as of wheezy it just no longer worked; the thread mismatches and the mismatches between the various AFS libraries were too severe. There's work in progress to fix this by building yet another profile of the AFS libraries, with all their warts, but in the meantime we needed access to the AFS PAG functions for various backend scripts. Everything else the Perl module did could be replaced by running the regular commands and parsing their output, but setpag has to be called in the process that should be affected to work safely. Hence this module. AFS::PAG provides a native Perl interface to the API exposed by libkafs and libkopenafs for PAG manipulation: hasafs, haspag, setpag, and unlog. (Eventually it might provide access to pioctl, but I haven't done that work yet.) It supports any platform that has a libkafs or libkopenafs, or Linux without either (by implementing the pioctl interface itself). You can get the latest version from the AFS::PAG distribution page.

10 September 2013

Julien Danjou: OpenStack Ceilometer Havana-3 milestone released

Last week, the third and last milestone of the Havana development branch of Ceilometer has been released and is now available for testing and download. This means the end of the OpenStack Havana development time is coming, and that the features are now frozen. New features
Eleven blueprints have been implemented as you can see on the release page. That's one more than during Havana-2, but it's less than was planned initially, though we had a pretty high score considering the size of our contributors team. I'm going to talk through some of them here, that are the most interesting for users. Bug fixes Fifty-six bugs were fixed, though most of them might not interest you so I won't elaborate too much on that. Go read the list if you are curious. Toward our final Havana release With the feature freeze in place, we're now focusing on fixing bugs and improving documentation. I'll try to make sure we'll get there without too much trouble for the 17th October 2013. Stay tuned!

7 September 2013

Daniel Pocock: Evacuating Australia

With the news that Australia's 100mbit (and potentially gigabit) fibre to the home is to be abolished and replaced with a cheap 25mbps service using Europe's ADSL hand-me-downs (which will be obsolete in 5 years when the deployment is finished), I've had quite a few emails from people asking just how easy it is to move abroad.
The acoustic modem has a nice retro look Word has got out that I've been spending some time in Switzerland enjoying the world-beating rate of IPv6 deployment. That is not the only reason to leave Australia of course, nor is it the only criteria for people choosing which country will give them a better deal than either of the two non-choices we had in Australia's elections. A free $20,000 for leaving Australia The first good news is that any recent graduate with a big bad ugly HECS bill is only obliged to pay this extra tax when they earn a salary from an Australian employer and file an Australian tax return. Australians who live abroad are not automatically obliged to file tax returns and are not slogged with this extra tax for having attended university. If somebody just graduated and has this hanging over their head, or if they've just started working and seen how much is being deducted on the payslip, moving abroad could make a lot of sense financially. If you have any moral qualms about this, just reflect on the fact that while the Government intimidates students with the feeling that they have to "pay" for fulfilling an education that makes them into a productive member of society, thousands of would-be athletes are given money with no obligation to repay it. The easiest route: a second passport One in four Australians has a parent born abroad. Most of those people qualify for a passport from their parent's country of birth. In some cases this also applies to people with grandparents born abroad. With the European Union now spanning 28 countries and guaranteeing the rights of any citizen from any country to live, work and study in any of the other 27 countries, a passport from any of the EU countries gives a lot of choices, including places where I have lived myself such as the UK, Ireland, France and Switzerland. Europe's citizen-friendly immigration In other words, an Australian with an Italian parent can go up to the Italian embassy in Canberra, collect an Italian passport and immediately fly into London and start working there with no bureaucratic delays, invasive and degrading medical checks or other Government interference in their life.
London's nightlife is popular for Australians. The UK started rolling out their high speed 21CN many years before Australia started the NBN. The rights also transfer automatically to all family members (spouse and children) - an Australian with a second passport is not restricted to living in Australia simply because they are married to somebody who does not have a second passport. As long as they arrive together at a European airport, they can simply show a marriage/birth certificate (in any language) and cross the border immediately, enjoy the same rights as a citizen, including work, study, healthcare and better broadband. No paperwork is necessary, no cottage industry for otherwise unemployable immigration agents, these are basic human rights for those living in Europe.
Eiffel tower: potentially part of the wireless network for France's new 4G internet, potentially two to four times the fixed-line speed planned for Australia's crippled broadband Uncle Sam wants more Australians Although it is not widely known, the US has a fast lane for immigration from Australia. The regular programs for skilled visas in the US are usually exhausted every year, whereas 10,000 "E3" class visas for Australians are never fully taken in any year. Surely it's not that easy to go to the US? It is. To qualify, an Australian only needs a university degree and a suitable job offer. Although the visa is for 2 years, it can be renewed and Australians who meet and marry an American have in various cases have gained full residence or citizenship. Anything is possible, you could even end up becoming a NASA Astronaut.
San Francisco, home to leading technology professionals and innovators from many countries. Some US cities such as Austin and Kansas City have let Google install fibre to the home, San Francisco could follow Working holiday schemes are not just for Britain Most Australians know somebody who went to London on a "working holiday" visa. These visas are not just for the UK and Australia has similar reciprocal programs with many other countries too. These rules for these schemes are rooted in the industrial age concept of workers with punch cards. Participants are typically limited to work 20 hours per week. Of particular interest for those in IT, such rules are hard to quantify for freelancers, web designers or creative people who earn their living charging fees per-project or undertaking management work without specified working hours. Although the visas are limited to 4 years, I've heard of Australians benefiting from the open borders of mainland Europe, spending 4 years in one country and then obtaining another 4 year visa for an adjacent country and travelling freely back and forth, building up a business and lifestyle of their own design. Singapore and Hong Kong Singapore and Hong Kong have become enormously popular destinations for Australians, particularly those with special skills in IT, finance, engineering and international business.
Singapore is respected as one of the cleanest and most orderly cities in Asia while embracing significant diversity in dining, shopping, leisure and lifestyle possibilities. They have recently boosted speeds to help people get a full 100MBit over fibre. A SIM card with high speed broadband charges SGD 7 (about $5) for 1 Gigabyte. These are not necessarily destinations that a graduate can easily move to. People are measured by their salary and the Government simply assumes that anybody earning a high salary is going to make a valuable contribution to society and they are given a visa in 1 or 2 weeks. Usually 3-5 years employment experience is required before making a move to one of these countries. The Not Ordinarily Resident (NOR) scheme gives some hints about the minimum salary level that ex-pats aim for, many earn significantly more with bonuses, stock programs and properly engineered tax-free offshore pension arrangements. These countries offer particularly low taxes (around 10%) and great technology. They have some rough edges too: like Europe, spouses are automatically given a visa too, but in contrast, their visa does not permit them to work unless they also work in a profession that is highly paid. Visas are issued quickly but they are also canceled very quickly if the job is terminated or the company goes bust. There have been various stories of people paying the typical 2-month deposit on an appartment in Singapore and then finding that it is forfeited when their job and visa are canceled and they have 4 weeks to leave. The bottom line is that people moving to these locations usually have a wide professional network and confidence to change their job quickly if necessary. Freestyle immigration and the visa run Not too long ago I was at a house party in Prague, Czech Republic, which is like a Paris of eastern Europe. Somebody introduced me to some Americans who I was told had similar interests in technology. They were operating an offshore web site and living very well. They had spent 10 years in Prague living on tourist visas. Authorities seemed quite happy for them to remain as long as they left every 3 months and spent 1 night abroad, a typical visa run. That could be as simple as a train journey to Vienna, Austria and an overnight stay.
Making a visa run in comfort and style with European railways. The Railjet train pictured includes free wifi, a lot cheaper than the $20 billion Tony Abbott plans to spend rolling out yesterday's technology in Australia When European countries abolished border controls, this system became much more convoluted for those who depend on the visa run. However, it remains common in many Asian and Latin American countries and many ex-pats live this way. Officials in many of these medium sized economies recognise the value of people bringing in money from offshore business (such as web sites) and using it to pay rent, food and local services. To make this effective, the ex-pats typically need to have an international private health insurance policy (high quality offshore policies can be found quickly with a search engine) and not aspire to work in a normal 9-5 job. Conclusion Young Australians might not want to just consider travel, it may even become unavoidable. The reality is, by 2020, one in three Australians will be a retired baby boomer and one way or another, whichever Government is in office will be unable to avoid taxing those of working age to pay for the health care and pension promises made to older generations. Serious expenditure on public infrastructure such as broadband or high speed rail appears to remain a pipe dream. Moving abroad, however, is just so much fun. Look at the way multinational companies make countries compete to attract their new factories and other projects: why should any individual citizen be any less demanding in choosing where they work, play and get the best value for whatever taxes they have to pay? Some people raise questions of patriotism or responsibility to the nation. Think again. The 200,000 Australians who live abroad or travel extensively make a significant contribution to Australia's international profile, engage in new trade initiatives, bring skills back to Australia and generally represent what our country is really about much better than some of those who are paid to do so.

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