Michael has been around for more than 10 years and has always contributed to the APT software family. He s the author of the first real graphical interface to APT synaptic. Since then he created software-center as part of his work for Ubuntu. Being the most experienced APT developer, he s naturally the coordinator of the APT team. Check out what he has to say about APT s possible evolutions. My questions are in bold, the rest is by Michael. Who are you? My name is Michael Vogt, I m married and have two little daughters. We live in Germany (near to Trier) and I work for Canonical as a software developer. I joined Debian as a developer in early 2000 and started to contribute to Ubuntu in 2004. What s your biggest achievement within Debian or Ubuntu? I can not decide on a single one so I will just be a bit verbose. From the very beginning I was interested in improving the package manager experience and the UI on top for our users. I m proud of the work I did with synaptic. It was one of the earliest UIs on top of apt. Because of my work on synaptic I got into apt development as well and fixed bugs there and added new features. I still do most of the uploads here, but nowadays David Kalnischkies is the most active developer. I also wrote a bunch of tools like gdebi, update-notifier, update-manager, unattended-upgrade and software-properties to make the update/install situation for the user easier to deal with. Most of the tools are written in python so I added a lot of improvements to python-apt along the way, including the initial high level apt interface and a bunch of missing low-level apt_pkg features. Julian Andres Klode made a big push in this area recently and thanks to his effort the bindings are fully complete now and have good documentation. My most recent project is software-center. Its aim is to provide a UI strongly targeted for end-users. The goal of this project is to make finding and installing software easy and beautiful. We have a fantastic collection of software to offer and software-center tries to present it well (including screenshots, instant search results and soon ratings&reviews). This builds on great foundations like aptdaemon by Sebastian Heinlein, screenshots.debian.net by Christoph Haas, ddtp.debian.org by Michael Bramer, apt-xapian-index by Enrico Zini and many others (this is what I love about free software, it usually adds , rarely takes away ). What are your plans for Debian Wheezy? For apt I would love to see a more plugable architecture for the acquire system. It would be nice to be able to make apt-get update (and the frontends that use this from libapt) be able to download additional data (like debtags or additional index file that contains more end-user targeted information). I also want to add some scripts so that apt (optionally) creates btrfs snapshots on upgrade and provide some easy way to rollback in case of problems. There is also some interesting work going on around making the apt problem resolver a more plugable part. This way we should be able to do much faster development. software-center will get ratings&reviews in the upstream branch, I really hope we can get that into Wheezy. If you could spend all your time on Debian, what would you work on? In that case I would start with a refactor of apt to make it more robust about ABI breaks. It would be possible to move much faster once this problem is solved (its not even hard, it just need to be done). Then I would add a more complete testsuite. Another important problem to tackle is to make maintainer scripts more declarative. I triaged a lot of upgrade bug reports (mostly in ubuntu though) and a lot of them are caused by maintainer script failures. Worse is that depending on the error its really hard for the user to solve the problem. There is also a lot of code duplication. Having a central place that contains well tested code to do these jobs would be more robust. Triggers help us a lot here already, but I think there is still more room for improvement. What s the biggest problem of Debian? That s a hard question I mostly like Debian the way it is. What frustrated me in the past were flamewars that could have been avoided. To me being respectful to each other is important, I don t like flames and insults because I like solving problems and fighting like this rarely helps that. The other attitude I don t like is to blame people and complain instead of trying to help and be positive (the difference between it sucks because it does not support $foo instead of it would be so helpful if we had $foo because it enables me to let me do $bar ). For a long time, I had the feeling you were mostly alone working on APT and were just ensuring that it keeps working. Did you also had this feeling and are things better nowadays ? I felt a bit alone sometimes That being said, there were great people like Eugene V. Lyubimkin and Otavio Salvador during my time who did do a lot of good work (especially at release crunch times) and helped me with the maintenance (but got interested in other area than apt later). And now we have the unstoppable David Kalnischkies and Julian Andres Klode. Apt is too big for a single person, so I m very happy that especially David is doing superb work on the day-to-day tasks and fixes (plus big project like multiarch and the important but not very thankful testsuite work). We talk about apt stuff almost daily, doing code reviews and discuss bugs. This makes the development process much more fun and healthy. Julian Andres Klode is doing interesting work around making the resolver more plugable and Christian Perrier is as tireless as always when it comes to the translations merging. I did a quick grep over the bzr log output (including all branch merges) and count around ~4300 total commits (including all revisions of branches merged). Of that there ~950 commits from me plus an additional ~500 merges. It was more than just ensuring that it keeps working but I can see where this feeling comes from as I was never very verbose. Apt also was never my only project, I am involved in other upstream work like synaptic or update-manager or python-apt etc). This naturally reduced the time available to hack on apt and spend time doing the important day-to-day bug triage, response to mailing list messages etc. One the python-apt side Julian Andres Klode did great work to improve the code and the documentation. It s a really nice interface and if you need to do anything related to packages and love python I encourage you to try it. Its as simple as: Of course you can do much more with it (update-manager, software-center and lots of more tools use it). With pydoc apt you can get a good overview. The apt team always welcomes contributors. We have a mailing list and a irc channel and it s a great opportunity to solve real world problems. It does not matter if you want to help triage bugs or write documentation or write code, we welcome all contributors. You re also an Ubuntu developer employed by Canonical. Are you satisfied with the level of cooperation between both projects? What can we do to get Ubuntu to package new applications developed by Canonical directly in Debian? Again a tricky question When it comes to cooperation there is always room for improvement. I think (with my Canonical hat on) we do a lot better than we did in the past. And it s great to see the current DPL coming to Ubuntu events and talking about ways to improve the collaboration. One area that I feel that Debian would benefit is to be more positive about NMUs and shared source repositories (collab-maint and LowThresholdNmu are good steps here). The lower the cost is to push a patch/fix (e.g. via direct commit or upload) the more there will be. When it comes to getting packages into Debian I think the best solution is to have a person in Debian as a point of contact to help with that. Usually the amount of work is pretty small as the software will have a debian/* dir already with useful stuff in it. But it helps me a lot to have someone doing the Debian uploads, responding to the bugmail etc (even if the bugmail is just forwarded as upstream bugreports IMO it is a great opportunity especially for new packagers as they will not have to do a lot of packaging work to get those apps into Debian. This model works very well for me for e.g. gdebi (where Luca Falavigna is really helpful on the Debian side). Is there someone in Debian that you admire for his contributions? There are many people I admire. Probably too many to mention them all. I always find it hard to single out individual people because the project as a whole can be so proud of their achievements. The first name that comes to my mind is Jason Gunthorpe (the original apt author) who I ve never met. The next is Daniel Burrows who I met and was inspired by. David Kalnischkies is doing great work on apt. From contributing his first (small) patch to being able to virtually fix any problem and adding big features like multiarch support in about a year. Sebastian Heinlein for aptdaemon. Christian Perrier has always be one of my heroes because he cares so much about i18n. Christoph Haas for screenshots.debian.net, Michael Bramer for his work on debian translated package descriptions.

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Thank you to Michael for the time spent answering my questions. I hope you enjoyed reading his answers as I did. Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Twitter and Facebook.

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The two first interviews were dedicated to long-time Debian developers. This time I took the opposite approach, I interviewed David Kalnischkies who is not (yet) a Debian developer. But he s contributing to one of the most important software within Debian the APT package manager since 2009. You can already see him in many places in Debian sharing his APT knowledge when needed. English is not his native language and he s a bit shy, but he accepted the interview nevertheless. I would like to thank him for the efforts involved and I hope his story can inspire some people to take the leap and just start helping My questions are in bold, the rest is by David. Who are you? I am David Kalnischkies, 22 years old, living in the small town Erbach near Wiesbaden in Germany and I m studying computer science at the TU Darmstadt. Furthermore I am for more than half a decade now young group leader of my hometown. I never intended to get into this position, but it has similarities with my career in this internet-thingy here. I don t remember why, but in April 2009 I was at a stage that some simple bugs in APT annoyed me so much that I grabbed the source, and most importantly I don t know why I did it but I published my changes in Mai with #433007, a few more bugs and even a branch on launchpad. And this public branch got me into all this trouble in June: I got a mail from Mr. package managment Michael Vogt regarding this branch A few days later I joined an IRC session with him and closely after that my name appeared for the first time in a changelog entry. It s a strange but also addicting feeling to read your own name in an unfamiliar place. And even now after many IRC discussions, bugfixes and features, three Ubuntu Developer Summits and a Google Summer of Code in Debian, my name still appear in places I have never even thought about e.g. in an interview. What s your biggest achievement within Debian? I would like to answer MultiArch in APT as it was my Google Summer of Code project, but as it has (not much) use for the normal user at this point will hopefully change for wheezy I chose three smaller things in squeeze s APT that many people don t even know yet:

• MMap run out of room , the most famous error related to the APT::Cache-Limit option is gone. The DynamicMMap in APT now deserves its name
• Download and usage of multiple Translations of Descriptions
• crazy stuff like apt-cache show ^apt-.*$/experimental works

If your impression is now that I only do APT stuff: that s completely right, but that s already more than enough for me for now as the toolchain behind the short name APT contains so many tools and use cases that you always have something different. You re an active member of the APT development team. Are there plans for APT in Debian Wheezy? What features can we expect? That s very hard to answer, as the team is too small to be able to really plan something. I mean, you can have fancy plans and everything and half a second later someone arrives on the mailing list with a small question which eats days of development time just for debugging But right now the TODO list contains (in no particular order):

• MultiArch managing packages built for different architectures like i386 on amd64 to ease the usage of packages which only work on specific architectures or cross-compiling.
• rewriting the subsystem responsible for downloading files to e.g. enable tools like apt-file or debtags to reuse the infrastructure by plugging into it.
• splitting long descriptions out of the Packages file to possibly decrease the size to download on an apt-get update . Includes mostly pulling the button only to enable it by the archive masters
• backporting popular features of some frontends to enable all frontends to use them, e.g. apt-get changelog or apt-get download
• support research on resolver improvements by implementing support for a distribution independent upgrade problem format (CUDF).
• an additional single binary for users wrapping apt-get, apt-cache and co.
• getting in contact (again) with various forks like apt-rpm and derivatives like maemo or telesphoreo to join forces instead of splitting them by working on different (and possibily very old) heads of the dragon

We will see what will get real for wheezy and what is postponed, but one thing is sure: more will be done for wheezy if you help! If you could spend all your time on Debian, what would you work on? I would spend it on APT s debbugs count zero would be cool to look at! We make progress in this regard, but with the current velocity we will reach it in ten years or so. Reading more mailing lists would be interesting, as I am kind of an information junky. Maintaining a package could be interesting to share the annoyance of a maintainer with handcrafted dependencies just to notice that APT doesn t get it in the way I intended it to be. Through, to make it feel real I need to train a few new APT contributors before so they can point my mistake out, but this unfortunately doesn t depend so much on time but on victims Maybe I could even be working on getting an official status. Beside that, I would love to be able to apt-get dist-upgrade the increasing mass of systems I and many others carry around in their pockets. In regards to my phone, this is already fixed, but there is much room for improvements. What s the biggest problem of Debian? You need to be lucky. You need to talk at the right time to the right person. That s not really a debian-only problem as such, but in a global project full of volunteers you can see it clearly as there are plenty of opportunities to be unlucky. For example, it s unlikely that an interview would be made with me now if Michael had not contacted me in June 2009. In a big project like Debian, you are basically completely lost without a mentor guiding you, so things like the debian-mentors list are good projects, but I am pretty certain they could benefit from some more helping hands. The other thing which I consider a problem is that and I read from time to time some people don t care for translations. That s bad. Yes, a developer is able to read English, otherwise s/he couldn t write code or participate on the mailinglists. Still, I personally prefer to use a translated application if I have the chance as it s simply easier for me to read in my mother tongue, not only because I am dyslexic, but because my mind still thinks in German and not in English. Yes, I could personally fix that by thinking in English only from now on, but its a quite big problem to convince my family which is not really familiar with tech-stuff to use something if they can t understand what is written on screen. It was hard enough to tell my mother how to write an SMS in a German interface. My phone with English words all over the place would be completely unusable for her despite the fact that my phone is powered by Debian and better for the task from a technical point of view. You are not yet an official Debian developer/maintainer, but you re already perceived in the community as one the most knowledgeable person about APT. It s a great start! What s your advice to other people who want to start contributing to Debian in general, and to APT in particular? It was never a goal in my life to start contributing . My goal was and still is to make my life easier by letting the computer work for me. At some point APT hindered the success of this goal, so it needed to be fixed. I didn t expect to open pandora s box. So, my advice is simple: Just start. Ignore the warning signs telling you that this is not easy. They are just telling you that you do something useful. Only artificial problems are easy. Further more, contribution to APT, dpkg or any other existing package is in no way harder than opening an ITP and working on your own, and it s cooler as you have a similar minded team around you to talk to. APT didn t accept release codenames as target release was one of the first things I fixed. If I had asked someone if that would be a good starting point the answer would have been a clear no , but I didn t search for a good starting point As a kid I can start playing football by just walking on the field and play or I can sit near the field, watching the others play, while analyzing which position would be the best for me to start ruling out one by one as the technical requirements seem too high Oh bicycle kick that sounds complicated I can t do that Julian Andreas Klode is working on a APT replacement, there s also Cupt by Eugene V. Lyubimkin. Both projects started because their authors are not satisfied with APT, they find APT s code difficult to hack partly due to the usage of C++. Do you share their concerns and what s your opinion on those projects? I don t think C++ is a concern in this regard, after all cupt is currently rewritten to C++0x and APT2 started in vala and is now C + glib last time I checked at least. I personally think that something is wrong if we need to advertise an application by saying in which language it is written The major problem for APT is probably that the code is old : APT does its job for more than 12 years now, under different maintainers with an always changing environment around it: so there are lines in APT which date from a time when nobody knew what a Breaks dependency is, that packages can have long descriptions which can be translated or even that package archives can be signed with a gpg key! And yet we take all those for granted today. APT has proven to adapt to these changes in the environment and became in this process very popular. So I don t think the point is near (if it will come at all) that APT can go into retirement as it is completely replaced by something else. The competitors one the other hand have their first 12 years still to go. And it will be interesting to see how they will evolve and what will be the state of the art in 2022 But you asked what I think about the competitors: I prefer the revolution from inside simply because I can see effects faster as more users will profit from it now. Cupt and co. obviously prefer the normal revolution. The goal is the same, creating the best package manager tool, but the chosen way to the goal is different. aptitude and cupt have an interactive resolver for example: that s something I dislike personally, for others that is the ultimate killer feature. cupt reading the same preference file as APT will have a different pinning result, which we should consider each time someone mentions the word drop-in replacement . APT2 isn t much more than the name which I completely dislike currently from a user point of view, so I can t really comment on that. All of them make me sad as each line invested in boilerplate code like configuration file parsing would be in my eyes better be spent in a bugfix or new feature instead, but I am not here to tell anyone what they should do in their free time But frankly, I don t see them really as competitors: I use the tools I use, if other do that too that s good, if not that s their problem. The thing that annoys me really are claims like plan is to remove APT by 2014 as this generates a vi vs. emacs like atmosphere we don t need. If some people really think emacs is a good editor who cares? I really hope we all can drink a beer in 2022 in Milliways, the restaurant at the end of the package universe, remembering the good old 2010 Is there someone in Debian that you admire for his contributions? No, not one, many! Michael Vogt who has nearly the monopole of package manager maintainer by being upstream of APT, synaptics and software center to name only the biggest and still has the time to answer even the dumbest of my questions. Jason Gunthorpe for being one of the initial developers behind deity who I will probably never meet in person beside in old comments and commit logs. Christian Perrier for caring so much about translations. Obey Arthur Liu as a great admin for Debian s participation in Google s Summer of Code. Paul Wise for doing countless reviews on debian-mentors which are a good source of information not only for the maintainer of the package under review. I guess I need to stop here because you asked for just one. So let s end with some big words instead: I am just a little cog in the big debian wheel

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Thank you to David Kalnischkies for the time spent answering my questions. I hope you enjoyed reading his answers as I did. Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Twitter and Facebook.

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I'm not sure of the exact date - if my memory serves me correctly, it was sometime during the summer of 1997 - I was given an account on Debian's server (located, at the time, in Beaverton, Oregon). I didn't go on to upload my first package until October of that year, as I had landed my first programming job at the same time, at CKS Partners. The "new maintainer process" in those days consisted of Klee Dienes calling me up and checking that I was a real person, had a pgp key, and wasn't completely clueless. It was a very different project in many ways than it is today - much smaller, much more informal, and of course much less well known in the world at large. Some elements were in place, though - my recollection is that the "flame friendly" atmosphere, while perhaps not quite as accentuated as it at times appears today, was firmly in place even back then. In '98, '99', and 2000, the Linux world was an exciting place to be. I still recall reading about the database companies deciding to release their products on Linux, reading The Cathedral and the Bazaar, and going to one of the first big commercial Linux conferences, in San Jose, in early 1999. Debian was well poised to take advantage of Linux's growth, too. Under Bruce Perens' leadership, several key elements of Debian had been put in place, like the social contract and free software guidelines. Fortuitously, Jason Gunthorpe was working on apt in that time period as well, which was another key element in Debian's success. One of the things I've always admired about Debian in the open source world is that it is in some ways a "stepping stone" project, meaning that it's a good way for people to start getting involved with free software, to get their toes wet "giving something back", without already being an expert hacker. It's easier to maintain a package of code, if you're willing to put in the time and attention to details, than to, say, write a new kernel module, or some other piece of critical C code. I've seen a number of people take this route - they get started with Debian, and as they go, learn more about the packages they work with, and perhaps even get involved with them "upstream", as they acquire skills and knowledge. By no means is everyone in Debian in that situation, though - there are some really first rate hackers, who tend to be the small core of people that really make Debian zing along. Indeed, being an autodidact in the world of computers, outside of one very forgettable term of C++ at Lane Community College, has given me an immense appreciation for the enormous opportunities open source affords in terms of learning - and especially hands-on learning. How many other fields let you work from anywhere in the world with an internet connection, with anyone else who is interested in the same subject, at whatever time you want, with tools that you can download entirely for free? It's really an intoxicating sensation realizing that you can do anything you want if you are willing to put the time in to learn how. The learning opportunities are one of the many things I'm grateful to Debian for. These days, I'm really not involved much with Debian anymore. I mostly run Ubuntu, which I think has perhaps improved on some of the social aspects of Debian (although Mark's zillions of dollars certainly play a large role, too). In terms of free software, I don't have as much time, and dedicate more of it to my own projects like Hecl. I still love the idea of open source software, but I'm also older and wiser (or more cynical?), and must face the reality that without scarcity, you have nothing to trade with others for things like food. Due to my lack of activity, perhaps I should resign, but ... I really don't want to, and who knows, maybe I'll have more time, and an "itch to scratch" at some point in the future. Who knows what the next ten years hold for Debian?