New comment by sgn on void-packages repository

https://github.com/void-linux/void-packages/issues/20393#issuecomment-611315658

Comment:
Worktree create by `git-worktree(1)` will use a file named `.git`, contains:

    gitdir: $XBPS_DISTDIR/.git/worktrees/<worktree-name>

In chroot, we couldn't navigate to that path, hence the errors.

We could fix this by mounting outer `$XBPS_DISTDIR` to inner