$ git clone -n https://src.fedoraproject.org/rpms/gimp-data-extras.git /var/lib/mock/f41-build-side-1-3128198-39561/root/chroot_tmpdir/scmroot/gimp-data-extras
Cloning into '/var/lib/mock/f41-build-side-1-3128198-39561/root/chroot_tmpdir/scmroot/gimp-data-extras'...
$ git fetch origin 6133aca8e0d56a1030b32ba790555b68121c331d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gimp-data-extras
 * [new ref]         6133aca8e0d56a1030b32ba790555b68121c331d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6133aca Fix building for GIMP version 3