fn git_in_repo(repo: &Path, args: &[&str]) -> Option<String>Expand description
Run git -C repo <args> with the ambient repo-location env scrubbed,
returning stdout on exit 0.
GIT_DIR / GIT_WORK_TREE / GIT_COMMON_DIR override -C outright,
so without the scrub a forge launched from a git hook, a git rebase --exec, or any shell that exported them answers every question about
every repo from one foreign repo - at exit 0, with nothing in the
output to say so.