Comment 6 for bug 1848354

Tested 1.1ubuntu1.18.04.12 on Bionic:

https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-bionic/bionic/amd64/u/unattended-upgrades/20191024_213859_e45c8@/log.gz
...
Allowed origins are: origin=Debian,codename=sid,label=Debian, origin=Debian,codename=sid,label=Debian-Security
An error occurred: 503 Service Unavailable
An error occurred: 503 Service Unavailable
The URI http://snapshot.debian.org/archive/debian/20171210T000000Z/pool/main/libe/libepoxy/libepoxy0_1.4.3-1_amd64.deb failed to download, aborting
The URI http://snapshot.debian.org/archive/debian/20171210T000000Z/pool/main/libe/libepoxy/libepoxy0_1.4.3-1_amd64.deb failed to download, aborting
Command exited with non-zero status 1
45.30user 1.77system 3:18.70elapsed 23%CPU (0avgtext+0avgdata 82468maxresident)k
632inputs+69168outputs (0major+43798minor)pagefaults 0swaps
autopkgtest [21:38:49]: test upgrade-between-snapshots: -----------------------]
autopkgtest [21:38:49]: test upgrade-between-snapshots: - - - - - - - - - - results - - - - - - - - - -
upgrade-between-snapshots FLAKY non-zero exit status 1
autopkgtest [21:38:49]: @@@@@@@@@@@@@@@@@@@@ summary
run-tests PASS
test-systemd.py PASS
upgrade-all-security PASS
upgrade-between-snapshots FLAKY non-zero exit status 1
Exit request sent.
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