$ git clone -n https://src.fedoraproject.org/rpms/gxmms2.git /var/lib/mock/f40-build-2218920-52622/root/chroot_tmpdir/scmroot/gxmms2
Cloning into '/var/lib/mock/f40-build-2218920-52622/root/chroot_tmpdir/scmroot/gxmms2'...
$ git fetch origin b5506c2c80b3373b759243b4794bfc3619f8cecd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gxmms2
 * [new ref]         b5506c2c80b3373b759243b4794bfc3619f8cecd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b5506c2 fix to build with xmms2 0.9.3