$ git clone -n https://src.fedoraproject.org/rpms/git.git /var/lib/mock/f40-build-1210994-22568/root/chroot_tmpdir/scmroot/git
Cloning into '/var/lib/mock/f40-build-1210994-22568/root/chroot_tmpdir/scmroot/git'...
$ git fetch origin 2bf676df03dea7a006ca027fd49129f1428782ce:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/git
 * [new ref]         2bf676df03dea7a006ca027fd49129f1428782ce -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2bf676d add glibc-utils BuildRequires