some trusty builds are failing because 'snapd' doesn't exist for this architecture

[Francis Ginther]

We have livefs builds failing with:

RUN: /usr/share/launchpad-buildd/slavebin/in-target buildlivefs --backend=lxd --series=trusty --arch=arm64 LIVEFSBUILD-114899 --project ubuntu-base --datestamp 20171114-140256 --image-format plain
Reading package lists...
Building dependency tree...
Reading state information...
Package snapd is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'snapd' has no installation candidate
Install failed
Traceback (most recent call last):
  File "/usr/lib/launchpad-buildd/lpbuildd/target/build_livefs.py", line 146, in run
    self.install()
  File "/usr/lib/launchpad-buildd/lpbuildd/target/build_livefs.py", line 91, in install
    self.backend.run(["apt-get", "-y", "install"] + deps)
  File "/usr/lib/launchpad-buildd/lpbuildd/target/lxd.py", line 427, in run
    subprocess.check_call(cmd, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 541, in check_call
    raise CalledProcessError(retcode, cmd)
CalledProcessError: Command '['lxc', 'exec', 'lp-trusty-arm64', '--', 'linux64', 'apt-get', '-y', 'install', 'livecd-rootfs', 'snapd', 'fuse']' returned non-zero exit status 100
RUN: /usr/share/launchpad-buildd/slavebin/in-target scan-for-processes --backend=lxd --series=trusty --arch=arm64 LIVEFSBUILD-114899
Scanning for processes to kill in build LIVEFSBUILD-114899
RUN: /usr/share/launchpad-buildd/slavebin/in-target umount-chroot --backend=lxd --series=trusty --arch=arm64 LIVEFSBUILD-114899
Stopping target for build LIVEFSBUILD-114899
RUN: /usr/share/launchpad-buildd/slavebin/in-target remove-build --backend=lxd --series=trusty --arch=arm64 LIVEFSBUILD-114899
Removing build LIVEFSBUILD-114899

The last successful build of this project on trusty was 2017-08-17, before the switch to lxd based builds I believe. We also see this on our ppc64el builds. Other architectures (amd64, i386, armhf and s390x work just fine. These builds also work on xenial and newer.

This issue is repeatable, I can point you to additional launchpad build logs if it helps.

[Michael Hudson-Doyle (mwhudson)]

This was fixed by https://code.launchpad.net/~cjwatson/launchpad-buildd/is-package-available-virtual/+merge/333104, just waiting on a rollout

[Colin Watson (cjwatson)]

Fixed in launchpad-buildd 156.