$ git clone -n https://src.fedoraproject.org/rpms/libgeopm.git /var/lib/mock/f42-build-3356258-45027/root/chroot_tmpdir/scmroot/libgeopm
Cloning into '/var/lib/mock/f42-build-3356258-45027/root/chroot_tmpdir/scmroot/libgeopm'...
$ git fetch origin 51a4595746d91127706865ba16a95542a19d46a9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libgeopm
 * [new ref]         51a4595746d91127706865ba16a95542a19d46a9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 51a4595 FTBFS fix (rhbz#2340735)