amend-upgpkg-commit.py

#!/usr/bin/env python3

import os
import git
import re
import sys
import subprocess

sha = sys.argv[1]

pattern = r'(.*): (.*) -> (.*)'

nixpkgs = os.path.join(os.environ['HOME'], 'nixpkgs')
repo = git.Repo(nixpkgs)
repo.git.add(all=True)

commit = repo.commit(sha)
message = commit.message

msg_first_line = message.splitlines()[0]
msg_https_line = ''

for line in message.splitlines():
    if line.startswith('https'):
        msg_https_line = line
        break

result = re.search(pattern, message.splitlines()[0])
pkg_attr = result.group(1)
org_from = result.group(2)
org_to = result.group(3)

new_to = subprocess.run(['nix', 'eval', f'{nixpkgs}#{pkg_attr}.version', '--raw'], stdout=subprocess.PIPE).stdout.decode()
print(new_to)

msg_https_line = msg_https_line.replace(f'{org_from}...{org_to}',f'{org_from}...{new_to}')

commit_message = f"""amend! {msg_first_line}

{pkg_attr}: {org_from} -> {new_to}

{msg_https_line}"""

index = repo.index
index.commit(commit_message)