Doesn't work with relative worktrees

[stessaris]

Due to a standing issue of libgit2, git-graph doesn't work on relative worktrees.

You might want raise an error as you already do for shallow clones in graph.rs.

I hope that libgit2 will be updated soon, because le lack of relative worktrees support is affecting a lot of tools depending on the library.

[peso]

Please describe what does not work and how to reproduce the bug. I'm not familiar with worktrees.

[stessaris]

@peso, sorry for the terse description of the issue, it was meant as an heads-up rather than something that should be tackled. Since this project relies (as many others) on libgit2 there's not much to do than waiting for them to fix the problem and then bump up the dependency.

In short, recent versions of git supports multiple working trees associated to the same (local) repo. Instead of the repo data in .git/, they use a link to the main .git/ directory. This is tracked in the repo, see Git - git-worktree Documentation for details. Relative worktrees use a relative instead of an absolute path to point to the .git/ directory; they are useful because they can be moved around and they are supported on some container based tools: if you copy in a container a worktree without the actual repo, the git support is going to be limited so you need also the main repo, this is difficult with full paths and easier with relative.

As to reproduce the bug, the steps are similar to my issue for nix:

Steps To Reproduce

Make sure you're using git version greater or equal than 2.48.0.

1. Create a git repo

   mkdir test && git -C test init && touch test/.gitkeep && git -C test add . && git -C test commit -m "Initial commit"

2. Verify that's working as expected:

   git -C test config --local --list
   git-graph -p test

3. Add a relative worktree:

   git -C test worktree add --relative-paths -b dev ../test.worktrees/dev
   git -C test worktree list -v

4. Now you get the error

   git -C test config --local --list
   git-graph -p test

   The error should be something like

   ERROR: unsupported extension name extensions.relativeworktrees
         Navigate into a repository before running git-graph, or use option --path
   

   Note the new line extensions.relativeworktrees=true in the local configuration.

Getting rid of relative worktree configuration will fix the problem:

git -C test.worktrees/dev worktree repair --no-relative-paths
git -C test config unset --local extensions.relativeworktrees
git-graph -p test