$ git clone -n https://src.fedoraproject.org/rpms/plasma-workspace-x11.git /var/lib/mock/f42-build-side-1-3586054-46913/root/chroot_tmpdir/scmroot/plasma-workspace-x11
Cloning into '/var/lib/mock/f42-build-side-1-3586054-46913/root/chroot_tmpdir/scmroot/plasma-workspace-x11'...
$ git fetch origin 9307cb1102723b3307c03bbc51afeff3c88330e0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-workspace-x11
 * [new ref]         9307cb1102723b3307c03bbc51afeff3c88330e0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9307cb1 Update to 6.4.2.