Impact: When a new Xenial installation attempts to update its appstream cache with an older version of apt-cacher-ng as its apt proxy, it will fail with error messages about invalid files/locations.
Fix: A small addition to the embedded patterns backported from a newer version of apt-cacher-ng allows to proxy appstream extensions again.
Testcase: Having an apt-cacher-ng proxy enabled for a Xenial system (might require to manually delete the cached files before) apt-get update will expose many 403 errors. After upgrading apt-cacher-ng those will download ok.
SRU Justification:
Impact: When a new Xenial installation attempts to update its appstream cache with an older version of apt-cacher-ng as its apt proxy, it will fail with error messages about invalid files/locations.
Fix: A small addition to the embedded patterns backported from a newer version of apt-cacher-ng allows to proxy appstream extensions again.
Testcase: Having an apt-cacher-ng proxy enabled for a Xenial system (might require to manually delete the cached files before) apt-get update will expose many 403 errors. After upgrading apt-cacher-ng those will download ok.