$ git clone -n https://src.fedoraproject.org/rpms/plasma-oxygen.git /var/lib/mock/f40-build-1509008-23893/root/chroot_tmpdir/scmroot/plasma-oxygen
Cloning into '/var/lib/mock/f40-build-1509008-23893/root/chroot_tmpdir/scmroot/plasma-oxygen'...
$ git fetch origin 6c3a9594f7fb353848ff3c24680e0f8ed59f9e97:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-oxygen
 * [new ref]         6c3a9594f7fb353848ff3c24680e0f8ed59f9e97 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6c3a959 6.1.2