Cannot use a remote theme on a branch with a "/" in the name

[JesseTG]

Describe the bug

When attempting to use a branch of a remote theme with a "/" in the name, Jekyll fails to generate the site. I don't have an error message right now, unfortunately.

Steps to reproduce the behavior

1. Create a branch on any remote theme, and ensure "/" is in the branch name.
2. Add remote_theme: user/themename@the/branch/name to your site's _config.yml
3. Generate the site

Expected behavior

The site should be generated normally.

Additional context

Work around this problem by not including slashes in branch names.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[pdmosses]

@benbalter This issue is annoying me, and I'd much appreciate it if the regexp used to match branch names could be as permissive as Git allows.

When a user submits a PR that I'd like to test, I need to build the test site using the user's branch. I generally prefer to use remote_theme instead of theme on the test site (to avoid the need to run bundle when testing different PR branches). But when the user's PR branch includes a /, I can't use remote_theme, and I need to switch to using theme.

Is there some reason for remote_theme not to support the use of branches, tags, and commits with all the names that Git allows?

BTW, I'm not a Ruby programmer, otherwise I'd submit a PR myself to try and fix this issue.