$ git clone -n https://src.fedoraproject.org/rpms/plasma-oxygen.git /var/lib/mock/f42-build-862341-170742/root/chroot_tmpdir/scmroot/plasma-oxygen
Cloning into '/var/lib/mock/f42-build-862341-170742/root/chroot_tmpdir/scmroot/plasma-oxygen'...
$ git fetch origin 15ee7cbb494da92c23430196dcc00fa20e7e550f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-oxygen
 * [new ref]         15ee7cbb494da92c23430196dcc00fa20e7e550f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15ee7cb 6.2.4