On Building 30K Debian Programs

On Building 30K Debian Programs

As fragment of my ongoing attempts to make some good datasets for coaching obliging code devices for C/C++, I’ve no longer too prolonged within the past been making an are trying to make every bundle in Debian Unstable from offer the utilization of endure to log the compilation and generate a compile_commands.json database for every make. Since it is no longer doubtless, in original, to parse C/C++ code with out sparkling what flags bear been worn (e.g., so yow will stumble on header files, know what preprocessor defines are in expend, etc.), this could originate up some good possibilities take care of:

  • Getting ASTs for every offer file
  • Rebuilding every file and generating its LLVM IR (-emit-llvm) or assembly (-S)
  • Extracting feedback connected with particular person capabilities

I’m going to potentially bear extra to say about this dataset after I no doubt accumulate around to doing something fun with it, nonetheless for now I desired to gorgeous jot down some notes on stuff I desire I had identified earlier than looking to originate that:

  • Isolation: Go the make for every bundle in some extra or much less isolated environment. how packages typically bear set up-time conflicts? It be 100x worse for make-time conflicts.
  • Expend an SSD: Be particular to make issues someplace with immediate storage. An excessive amount of compiling stuff is gorgeous reading it off disk and writing it relieve. Because my most major Docker stores its photos on spinning rust, I ran a separate Docker daemon for the SSD with a minimal config file. Then you definately would per chance gorgeous house DOCKER_HOST=unix:///var/lumber/docker-nvme.sock and make/lumber your photos.
  • Log all the pieces, particularly exit codes. I got thru a entire move earlier than realizing I didn’t bear a legit approach to repeat which packages had built successfully (dpkg-buildpackage emits an exhilarating array of inconsistent messages), and had to re-lumber all the pieces.
  • Flip off stuff you originate no longer desire. I originate no longer care about working exams or building documentation, so I house DEB_BUILD_OPTIONS=”nodoc notest nocheck”. Sadly, no longer every bundle respects the make alternatives, on the other hand it is worth a are trying.
  • Design no longer make as root. Masses of packages detect whenever you might doubtless also very neatly be looking to make stuff as root and must die (coreutils is one instance). Right here is a actually easy mistake to achieve in Docker, the attach working as root is the default. Go as a favorite person, and expend “dpkg-buildpackage -rfakeroot” in direct that it could pretend to be root for packages that originate are looking to be built as root.
  • Go non-interactively. There are a pair of packages that, when place in, are trying to inquire the person some questions and must hang forever except DEBIAN_FRONTEND=noninteractive is determined. So house it, and be particular it will get handed on child processes (an especially stressful instance is sudo, the attach you desire so as to add -E to achieve it inherit the environment).
  • Expend timeouts. In particular in an isolated environment take care of Docker, typically stuff will gorgeous hang at some stage in make (or maybe in some cases it is endure’s fault, IDK). Some original culprits I’ve realized to this level are xvfb-lumber and erl_child_setup, and (maybe) issues that demand dbus to be most up-to-date. Besides environment a timeout, I also ran a script within the background to earn and homicide any of those processes that bear been striking around longer than a tiny while. [Actually, rather than killing them, which will make them exit with a non-zero status and cause the build to error out, I used this nice trick from Kyle Huey to attach to them with gdb and inject a call to exit(0)]
  • Horny up. Because you might doubtless also very neatly be the utilization of a good immediate SSD, it is potentially no longer huge (mine is a measly 2TB). Builds are substantial. You doubtless can are looking to preserve in mind to maneuver your make artifacts to someplace roomier in direct that you just originate no longer lumber out of web site (this tends to achieve make programs very unhappy).
  • Conclude up to this level. At the starting up I gorgeous parsed Sources.gz, grabbed your total offer packages, after which tried to accumulate their make-deps. However it appears to be like Debian strikes too immediate for this; by the level I got around to building some bundle a pair of days later, its make-deps had in some cases been up up to now and weren’t available in kindly any extra. Now I as an alternative initiate every make with an kindly-accumulate -y change, after which accumulate the latest sources bundle records and make dependencies gorgeous earlier than making an are trying the make.
  • Protect some distance off from shell hackery. Right here would per chance very neatly be controversial, and I’m particular somebody better and additional cautious at bash would per chance doubtless originate it, nonetheless looking to automate all the pieces in a language the attach mess ups are restful and can originate titillating issues take care of call “rm -rf /” in case you meant “rm -rf ${foo}/${bar}” is painful. Python has its bear considerations, on the other hand it modified into good to no longer decrease than accumulate noisy errors as almost right this moment as issues went tainted (instance script: this one which makes expend of python-kindly to accumulate offer bundle records, in desire to “parsing” Sources.gz with grep/awk/sed).
  • Ask to be disappointed. Even in any case of this a lot of stuff goes to fail to make. Varied issues can be unusual in ways you in no diagram dreamed software program can be unusual (hello, packages that expend 12 hours generating documentation the utilization of xsltproc!). Yow will stumble on fun stuff take care of packages that bear particular safety vulnerabilities, as published by compiler diagnostics take care of -Wformat-safety (presumably these packages built gorgeous below older, dumber compilers). Some of this could potentially be mitigated by focused on Debian stable; unstable is, neatly, unstable, and brokenness is anticipated.

Absolute self perception I’ve missed hundreds issues that bear this a extra magnificent and legit expertise! There are a lot of quite a pair of initiatives which can be also making an are trying to make all (or obliging portions) of Debian, which I potentially must bear looked at in extra detail earlier than making an are trying to roll my bear (my ideal excuse is that I needed something I knew straightforward programs to lengthen and regulate to originate unusual stuff take care of tracing make instructions and recompiling particular person files with quite a pair of flags):

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“Simplicity, patience, compassion.
These three are your greatest treasures.
Simple in actions and thoughts, you return to the source of being.
Patient with both friends and enemies,
you accord with the way things are.
Compassionate toward yourself,
you reconcile all beings in the world.”
― Lao Tzu, Tao Te Ching