$ git clone -n https://src.fedoraproject.org/rpms/libfm.git /var/lib/mock/f41-build-841092-161062/root/chroot_tmpdir/scmroot/libfm
Cloning into '/var/lib/mock/f41-build-841092-161062/root/chroot_tmpdir/scmroot/libfm'...
$ git fetch origin fee91f19c3a96f12e174be02dca0238fa9e761a9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libfm
 * [new ref]         fee91f19c3a96f12e174be02dca0238fa9e761a9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fee91f1 Update to the latest git