$ git clone -n https://src.fedoraproject.org/rpms/libarchive.git /var/lib/mock/f40-build-730581-103522/root/chroot_tmpdir/scmroot/libarchive
Cloning into '/var/lib/mock/f40-build-730581-103522/root/chroot_tmpdir/scmroot/libarchive'...
$ git fetch origin d8064ce9e93059f92b1134823cd1eb65452b148e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libarchive
 * [new ref]         d8064ce9e93059f92b1134823cd1eb65452b148e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d8064ce Rebase to version 3.7.2