$ git clone -n https://src.fedoraproject.org/rpms/merkaartor.git /var/lib/mock/f42-build-862952-171273/root/chroot_tmpdir/scmroot/merkaartor
Cloning into '/var/lib/mock/f42-build-862952-171273/root/chroot_tmpdir/scmroot/merkaartor'...
$ git fetch origin a9fc9a38177502b14551c02d22f3b52e5edbcfd6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/merkaartor
 * [new ref]         a9fc9a38177502b14551c02d22f3b52e5edbcfd6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a9fc9a3 Rebuild (GDAL)