feat: add ability to downgrade aur package using git

[darukutsu]

Checklist

• Admin:
  • No duplicate PRs
• Integration:
  • Always add unit tests for fixes or new functionality
  • If adding new options, update dist/completion/*
• Documentation:
  • If adding new options, update usage and doc/*.ronn
  • If adding new strings, update locale/*.po

Description

If you don't store all tarballs in your ~/.cache/yay (like me, store only last 2) or if you use other aur-manager you could instead use vcs to switch to desired branch and rebuild chosen version. Hopefully everything works as should, tested only for yay.

[darukutsu]

Added some tests, however i don't understand yet how syntax works, so will edit them when I figure out.

[pbrisbin]

This is looking good. Sorry, I should've warned you not to worry about the existing shfmt / shellcheck stuff.

[darukutsu]

I realized that makepkg -fs outputs correct pkg name so no more need to rename and rename back to use gitpkg... now its literally placeholder for build_pkg() to determine whether it should be build. File with gitpkg never exists. So only what we need to alter is to_install array and I come up with safe solution. That previous renaming using -ctime wasn't imo very good solution.

see

593: printf "%s\0" "$item" >> new_to_install.downgrade

613: mapfile -d '' to_install < new_to_install.downgrade
614: rm new_to_install.downgrade

Here's simple command how to try build something from aur

 $ downgrade --git --pacman-cache ~/.cache/yay --maxdepth 2 'ani-cli>4.7' bash