It seems that there was an oversight when implementing the branch name parsing in ENVBUILDER_GIT_URL resulting in an inability to use a specific branch when cloning using an SSH URL.

Could we look into implementing this?

When I work with a public repository and use HTTPS, everything works fine. I can clone the main branch and even specify another branch, as described in the documentation, like this:
ENVBUILDER_GIT_URL=https://github.com/coder/envbuilder-starter-devcontainer/#refs/heads/my-feature-branch
However, when I switch to a private repository that requires SSH authentication, I can successfully clone the main branch, but I'm unable to specify a different branch (e.g., sample-branch). Here's the Git URL format I'm using for the private repo:

ENVBUILDER_GIT_URL=[email protected]:your-group/your-repo.git/#refs/heads/sample-branch

(https://discord.com/channels/747933592273027093/1354136229498585158/1354136229498585158)