$ git clone -n https://src.fedoraproject.org/rpms/biber.git /var/lib/mock/f42-build-3302520-41426/root/chroot_tmpdir/scmroot/biber
Cloning into '/var/lib/mock/f42-build-3302520-41426/root/chroot_tmpdir/scmroot/biber'...
$ git fetch origin 24c2771d82e1645e3fdc9b2962be3d28bd83abfe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/biber
 * [new ref]         24c2771d82e1645e3fdc9b2962be3d28bd83abfe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 24c2771 2.20 bump