$ git clone -n https://src.fedoraproject.org/rpms/plasma-thunderbolt.git /var/lib/mock/f42-build-side-1-3555050-46650/root/chroot_tmpdir/scmroot/plasma-thunderbolt
Cloning into '/var/lib/mock/f42-build-side-1-3555050-46650/root/chroot_tmpdir/scmroot/plasma-thunderbolt'...
$ git fetch origin 013330fc09f698ee13c55718c2d7f8053a4c6a5a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-thunderbolt
 * [new ref]         013330fc09f698ee13c55718c2d7f8053a4c6a5a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 013330f 6.4.0