Add pipx install github pull request support

How would this feature be useful?

pipx is for end users. end users typically don’t understand how to figure out repo and branch of a pull request

Describe the solution you’d like

pipx install https://github.com/pypa/pipx/pull/794

Describe alternatives you’ve considered

The alternative, the current is to:

1. open pr
2. figure out source repo
3. figure out branch name
4. build git+https url
5. pipx install that url

• https://pypa.github.io/pipx/#installing-from-source-control

and even advanced users have trouble doing that:

pipx install git+https://github.com/meowmeowmeowcat/pipx@fix-#781

oh, glad I picked that example. some shells may need to deal with escapes, like # for UNIX, ^ for windows

also, once the PR is merged, and the branch deleted the branch name option won’t work, would need to use git hash of the last commit or merge commit.

for initial implementation having support for open PR’s would be already big step forward.

[tony]

Why would an end user want to install from a pull request? This seems like an exceedingly rare use case.

@cs01 This would be incredibly helpful. Here’s an example:

https://github.com/python-poetry/poetry/pull/4852#issue-1066910051

Install with pipx:

pip install pipx
pipx install --suffix=@pyenv 'poetry @ git+https://github.com/finswimmer/poetry.git@proof-of-concept-pyenv'
poetry@pyenv --version

When there’s an bug or improvement, this can be used to get the users in the issue to test the pull request easily.

This saves a ton of effort. gh pr checkout has a similar utility.

I’m stunned this doesn’t already exist. 🤷 I’m fine with doing it manually in the mean time by hand, but when reviewing lots of PRs this would save time.

Edit: NPM / yarn has a convention for this at https://stackoverflow.com/a/36743127/1396928

[glensc]

Update: This usage works:

➜ pipx install --suffix=@pr 'git+https://github.com/Taxel/PlexTraktSync@refs/pull/838/head'
  installed package PlexTraktSync 0.18.0.dev0 (PlexTraktSync@pr), installed using Python 3.10.2
  These apps are now globally available
    - plextraktsync@pr
done! ✨ 🌟 ✨

But projects need to be installable from git branch:

• https://github.com/Taxel/PlexTraktSync/pull/838