https://gerrit.wikimedia.org/r/#/c/268563/ caused debian-glue to fail with (https://integration.wikimedia.org/ci/job/debian-glue/82/console):
[…] 16:24:16 Writing extended state information... 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main libpython3.4-minimal amd64 3.4.3-8 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main libpython3.4-stdlib amd64 3.4.3-8 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main python3.4-minimal amd64 3.4.3-8 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main python3-minimal amd64 3.4.3-4 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main python3.4 amd64 3.4.3-8 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main libpython3-stdlib amd64 3.4.3-4 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main dh-python all 2.20150826 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main python3 amd64 3.4.3-4 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main distro-info-data all 0.27 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:16 Err http://mirrors.wikimedia.org/debian/ sid/main lsb-release all 9.20150917 16:24:16 404 Not Found [IP: 208.80.154.10 80] 16:24:17 E: Failed to fetch http://mirrors.wikimedia.org/debian/pool/main/p/python3.4/libpython3.4-minimal_3.4.3-8_amd64.deb: 404 Not Found [IP: 208.80.154.10 80] 16:24:17 E: Unable to correct for unavailable packages […]
This is because mirrors.wikimedia.org sid/main provides the package libpython3.4-minimal_3.4.4-2_amd64.deb, not -3.4.3-8. Apparently, apt-get update has not been run on the hosts trying to build the package so obsolete information has been kept around.
I stumbled over this the first time about 15 hours ago, so cron should have run apt-get update since then as part of /usr/local/sbin/puppet-run, so I assume the hosts running the package builds are configured in a different way.