Vinaigrette

Build those damn .deb's

How this shit works

The build chain relies on sbuild, a wrapper tool for building the .deb, and reprepro to handle the apt repo part (signing and serving)

1. Initially, some chroots are prepared, one per available distribution (buster, bullseye, ...), pre-installed with build dependencies to speed up builds. See the scripts/make-chroots script.
2. reprepro is configured in /var/www/repo/debian/conf/distributions. In this file, you'll find the supported distributions (aka codenames), and branches (aka components: stable, testing, unstable). It also declares what GPG key to use to sign the repo.
3. Upstream codes are kept in gitrepos/
4. Builds are launched, either manually via ./ynh-build and scripts/ynh-custom-builds - or via a cron job (c.f. ./daily-build which in fact runs every 15ish mins?)
   • These scripts usually perform consistency checks, or tweak the changelog / version number, and then call scripts/build_deb, itself calling sbuild and reprepro include
   • In the most simple case, the software being build is arch-independent, such as Python. In that case, it is pretty straightforward : sbuild starts the chroot, in which build dependencies are installed, and dpkg-buildpackage is called.
   • In more complex cases, the software is arch-dependent. In that case, sbuild is called multiple times with --host=$arch. It will still run in the same amd64 chroot, but will install dependencies for the foreign architecture (such as the C compiler for armhf, or lib-foobar-dev for armhf), and build the package using these.
   • For every .deb/.changes generated, reprepro include is called to add the new build to the apt repo. The builds are signed with the key declared in conf/distributions.
5. ???
6. PROFIT!

Troubleshooting

Debugging apt/dpkg being in broken state in the chroot

If you savagely Ctrl+C during a build, dpkg/apt may end up in a broken state

You can debug this by entering the chroot with schroot -c $DIST-amd64-sbuild

Relaunching a build manually with a shell ?

If a build fails and needs to be debugged, you should run export DEBUG=true, and re-run the appropriate build command. This should add the option --anything-failed-commands='%s' to the sbuild command, which will then drop you in an interactive shell inside the chroot, right after the failure. This should help investigate what's happening.

Removing "conflicting" sources

• Sometimes reprepro is an ass and wont let you add some sources because a supposedly more recent version already exists
• To make it happy, you can use the undocumented removesrc feature :

# From the folder /var/www/repo/debian
reprepro removesrc <codename> <source-package-names> [<source-version>]

# For instance
 reprepro removesrc stretch yunohost-admin 3.0.0+201804281857

Removing a deb package from the repo

reprepro remove <codename> <package>

# For instance, from anywhere
reprepro -Vb /var/www/repo/debian remove buster python3-miniupnpc

(-Vb /var/www/repo/debian is where the repo is stored)