+def git_fetch(v: Verification, channel: Channel) -> None:
+ # It would be nice if we could share the nix git cache, but as of the time
+ # of writing it is transitioning from gitv2 (deprecated) to gitv3 (not ready
+ # yet), and trying to straddle them both is too far into nix implementation
+ # details for my comfort. So we re-implement here half of nix.fetchGit.
+ # :(
+
+ # TODO: Consider using pyxdg to find this path.
+ channel.git_cachedir = os.path.expanduser(
+ '~/.cache/nix-pin-channel/git/%s' %
+ digest_string(
+ channel.url.encode()))
+ if not os.path.exists(channel.git_cachedir):
+ v.status("Initializing git repo")
+ process = subprocess.run(
+ ['git', 'init', '--bare', channel.git_cachedir])
+ v.result(process.returncode == 0)
+
+ v.status('Checking if we already have this rev:')
+ process = subprocess.run(
+ ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_commit])
+ if process.returncode == 0:
+ v.status('yes')
+ if process.returncode == 1:
+ v.status('no')
+ v.result(process.returncode == 0 or process.returncode == 1)
+ if process.returncode == 1:
+ v.status('Fetching ref "%s"' % channel.git_ref)
+ # We don't use --force here because we want to abort and freak out if forced
+ # updates are happening.
+ process = subprocess.run(['git',
+ '-C',
+ channel.git_cachedir,
+ 'fetch',
+ channel.git_repo,
+ '%s:%s' % (channel.git_ref,
+ channel.git_ref)])
+ v.result(process.returncode == 0)
+ v.status('Verifying that fetch retrieved this rev')
+ process = subprocess.run(
+ ['git', '-C', channel.git_cachedir, 'cat-file', '-e', channel.git_commit])
+ v.result(process.returncode == 0)
+
+ v.status('Verifying rev is an ancestor of ref')
+ process = subprocess.run(['git',
+ '-C',
+ channel.git_cachedir,
+ 'merge-base',
+ '--is-ancestor',
+ channel.git_commit,
+ channel.git_ref])
+ v.result(process.returncode == 0)
+
+