$ git clone -n https://src.fedoraproject.org/rpms/mame.git /var/lib/mock/f40-build-791254-137272/root/chroot_tmpdir/scmroot/mame
Cloning into '/var/lib/mock/f40-build-791254-137272/root/chroot_tmpdir/scmroot/mame'...
$ git fetch origin 59c4d6e36ce4ab1fe345212e698a2306ff34d94f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mame
 * [new ref]         59c4d6e36ce4ab1fe345212e698a2306ff34d94f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 59c4d6e Upload sources