$ git clone -n https://src.fedoraproject.org/rpms/mingw-gtk3.git /var/lib/mock/f42-build-3460618-45515/root/chroot_tmpdir/scmroot/mingw-gtk3
Cloning into '/var/lib/mock/f42-build-3460618-45515/root/chroot_tmpdir/scmroot/mingw-gtk3'...
$ git fetch origin 02ba8cb0c683242abf8c4d355cd2715b93e3da45:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mingw-gtk3
 * [new ref]         02ba8cb0c683242abf8c4d355cd2715b93e3da45 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 02ba8cb Fix sourcedir name