Those who have spoken to me know that I’m not a big fan of packages for shipping software. Once upon a time, I was wowed that I could simply
emerge blender and have a full 3D modelling suite running in a few minutes, without the fuss of wizards or unchecking boxes seeing the README. But today, iOS and Android have redefined the app installation experience, and packages seem like a step backwards.
I’m not alone in this. If you’ve seen recent conversations about the systemd team’s proposal for shipping Linux software differently, they’re effects of the same lunchtime conversations and gripes on IRC.
My goal here is to explain the problems we’ve seen, map out some goals for a new solution to supercede packages, and open up an avenue for discussion about this.
As a user
Dealing with packages as a normal user can be really frustrating. Just last week I had the frustrating experience of trying to upgrade my system when Debian decided to stop in the middle, ask me a question about which sshd configuration file I wanted to keep out of the two. I left it like that and went to lunch, and when I got back I accidentally hit the power strip with my feet. After much cursing, I eventually had to reinstall the OS from scratch.
It should never be possible to completely hose your OS by turning it off during normal operation, and I should be able to upgrade my OS without having the computer ask me incomprehensible questions I don’t understand.
And on my Fedora laptop, I can’t upgrade my system because Blender used an older libjpeg than my system. It gave me some error about packages conflicting and then aborted. And today, as I’m writing this, I’m on an old, insecure Fedora installation because upgrading it takes too much manual effort.
Today’s package managers do not see the OS independently from the applications that make it up: all packages are just combined to create one giant filesystem tree. This scheme works great when you have a bunch of open-source apps you can rebuild at every ABI break, but it’s not great when trying to build a world-class OS.
It’s also partially because package installations aren’t reproducible. Installing package A and then package B does not guarantee the same filesystem tree as installing package B, then A.
Packages are effectively composed of three parts: metadata about the package (its name, version, dependencies, and plenty of other information), a bunch of files to place in the filesystem tree (known as the “payload”), and a set of scripts to run when installing, uninstalling and upgrading the package (known as the “triggers”). It’s because of these scripts that packages are dangerous.
It would be great if developers could ship their apps directly to users. But, unfortunately, packaging gets in the way. The typical way to do things is to package up the source code, and then let community members who are interested make their own package for their favorite “distribution”. Each distribution usually has its own package format, build system, different payloads and triggers, leading to a frustrating fragmentation problem for both users and developers.
The developers of Chromium, for instance, doesn’t allow any bugs to be reported for any builds but their official version, since they can’t be sure what patches the community has made. And in some ases, the community has patched a lot. (Side note: I find it personally disappointing that a great app, Chromium, isn’t shipped in Fedora because of disagreements in how their app is developed. Fedora should stand for freedom and choice for the user to use whatever apps they want, and not try to force their engineering practices on the world.)
As a developer
That said, packages are amazing when doing development. Want to read PNGs?
apt-get install libpng-devel. Want a database? Instead of hunting around for SQLite binaries, just
yum install 'pkg-config(sqlite3)'.
Paired with pkg-config, I think the usability and ease of use have made it quite possibly the most attractive development environment out there today. In fact, other projects like node’s npm, Ruby’s gems, and Python’s pip have stolen the idea of packages and made it their own. Even Microsoft has endorsed NuGet as the easiest way of developing great apps on top of
their .NET platform.
Development packages solve a lot of the typical problems. These libraries are directly uploaded by developers, and typically are installed per-project, not globally across the entire system, meaning I can have one app built against an older SQLite, and another building something more modern. Upgrading these packages don’t run arbitrary scripts as root, they just unpack new files in a certain location.
I’ve also doing a lot of recent development on my ThinkPad and my home computer, both being equipped with SSDs without a lot of disk space. While I happily welcome HP’s memristors to hit shelves and provide data storage in sizes and speeds better than today’s SSDs, I think it’s worth thinking about how to provide a great experience for those not as fortunate to waste another gig on duplicated libraries.
Working towards a solution
With all of this in mind, we can start working on a solution that solves all these problems and meets these goals. As such, you might have seen different things trickle out of the community here. The amazing Colin Walters was the first to actually do my former employeranything when he built OSTree, which allows fully atomic system upgrades. You can never get your system into a hosed state with it.
At Endless Mobile, we want to ship a great OS that upgrades automatically, without ever breaking if the power gets cut or if the user unplugs it from the wall. We’ve been using OSTree successfully in production, and we’ve never seen a failed upgrade in the wild. It would be great to see the same applied to applications.
As mentioned, we’ve also seen some work starting on the app experienced. Lennart Poettering started working on Sandboxed Applications for GNOME back in 2013, and work has steadily been progressing, both on building KDBus for sandboxed IPC, and a more concrete proposal for how this experience will look and fit together.
Reading closely, you might pick up that I, personally, am not entirely happy with this approach, since there’s no development packages, and a number of other minor technical criticisms, but I haven’t really talked about to Lennart or the rest of the team building that yet.
I also know that this is controversial. Wars have been fought over package management systems and distributions, and it’s very offputting for someone who just wants to develop software for our platform and our OS.
Package managers aren’t magic, they’re a set of well-understood technical tools, with tradeoffs and limitations like every other system out there. I hope we can move past our differences, recognize issues in existing technology, and build something great together.
As always, these opinions are my own. I do not speak for anybody mentioned in this article, anybody else in the GNOME community, the opinion of GNOME in general, and I certainly don’t speak for either my current employer or my former employer.
Please feel free to express opinions in the comments, for or against, however strong, as I’m honestly trying to open an avenue of discussion. However, I will not tolerate comments that make personal attacks on anybody. My blog is not the place for that.