--separate-git-dir
Make git module support --separate-git-dir option. When git version is higher than 1.7.5, use built-in --separate-git-dir option during the clone. When lower, adjust the location of git dir manually after clone to achieve the same effect.
PR #38016 Co-authored-by: Sviatoslav Sydorenko <wk.cvs.github@sydorenko.org.ua>