git_repository: while in a context manager, an exception can be raised
Even if handled by the caller of the context manager, the context
manager itself has exited at that point and won't necessary do its
symmetrical cleanup.
In temporary_worktree we need to chdir before re-raising.
In pristine_tar_branches we need to restore the pristine-tar branches.
It is incorrect to use an empty list in the argument definition,
as all callers share the same empty list. While we do not modify
that list currently, in run(), there is no guarantee that we will
not in the future.
GitUbuntuRepository::temporary_worktree: prune after deleting tempdir
This is a bugfix for pruning worktrees in temporary_worktree. While the
worktrees are all pruneable after commands return, the issue with our
call to `git worktree prune` is that it occurs within the
TemporaryDirectory context manager, which means the temporary worktree
is not yet pruneable (the directory containing the worktree must be
deleted for pruning to succeed).
The former is unused and the latter is only used for a debugging print
statement.
Annotated tags contain an internal tag name, which is stored in the
object. This means that the name of the tag when the tag is created is
maintained, regardless of local renames. This is a problem for `git
describe`, and other similar functions, which might rely on the tag name
being useful locally; since that's not true, drop the use. If it turns
out to be needed later, we can re-add them.
