$ git clone -n https://src.fedoraproject.org/rpms/free42.git /var/lib/mock/f39-build-1751436-41466/root/chroot_tmpdir/scmroot/free42
Cloning into '/var/lib/mock/f39-build-1751436-41466/root/chroot_tmpdir/scmroot/free42'...
$ git fetch origin 2192cf278587ceaa24aac681dcb023d3ee1227ad:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/free42
 * [new ref]         2192cf278587ceaa24aac681dcb023d3ee1227ad -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2192cf2 Update to 3.1