External dependencies make the build more painful for developers and CI
in different environments, so we've agreed to prefer avoiding external
dependencies where possible.
Since launchpadlib is now fixed in Bionic, the orig tarball with the fix
is hosted on Launchpad indefinitely, so we can use it to reduce external
snap build dependencies.
The fix the sole change in new upstream version 1.10.6, so bump
git-ubuntu's setup.py to require that version.
Since Nish has left, his people.c.c space has been removed. Replace the
caching using my space instead. Also cache many other orig tarballs that
are unreachable directly from my test system.
This also locks in the new dpkg vendored tarball by hash to move the
trust requirement to this file only.
find_ubuntu_merge_base: fix the code for the new imported Git layout
We no longer have a publishing parent to use as a Git merge-base, so we
have to rely on what we know about Ubuntu merges. We look for the
nearest (searching the changelog backwards) Debian version that has been
imported. That should provide us a delta point.
Note the underlying importer changes also changes a necessary step in
the merge workflow, which has been updated on the wiki (use of --onto to
`git-rebase`).
This abstraction allows for unit-testing. This also adjusts the
parameter types and return types (including adding a docstring!) which
feels more natural with other methods now.
