`archive.ubuntu.com/ubuntu/pool/main` only keeps the current version of a
package, so the pinned `zlib1g 1:1.3.dfsg-3.1ubuntu2.1` URL started 404ing.
`curl` without `-f` wrote the error page into `zlib1g.deb` and exited 0, so
the fixture image built clean and just contained a non-deb, failing
`TestDpkgArchiveCataloger` only when the fixture cache was cold.
Now points at the launchpad `+files` URL, which is immutable. Also added `-f`
to the other fixture Dockerfiles that curl a pinned artifact so the next bit
of URL rot fails the build instead of quietly poisoning a fixture.
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>
Alex Goodman
9e520d1442