$ git clone -n https://src.fedoraproject.org/rpms/gpaw.git /var/lib/mock/f39-build-2118494-50726/root/chroot_tmpdir/scmroot/gpaw
Cloning into '/var/lib/mock/f39-build-2118494-50726/root/chroot_tmpdir/scmroot/gpaw'...
$ git fetch origin 8a9874dd396fb07b708b42f7982c4f71b5b90e02:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gpaw
 * [new ref]         8a9874dd396fb07b708b42f7982c4f71b5b90e02 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a9874d New upstream release