$ git clone -n https://src.fedoraproject.org/rpms/plasma-thunderbolt.git /var/lib/mock/f42-build-side-1-3499903-45966/root/chroot_tmpdir/scmroot/plasma-thunderbolt
Cloning into '/var/lib/mock/f42-build-side-1-3499903-45966/root/chroot_tmpdir/scmroot/plasma-thunderbolt'...
$ git fetch origin 071a3ef97891c11fd15b570c20d098bef5faf87d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-thunderbolt
 * [new ref]         071a3ef97891c11fd15b570c20d098bef5faf87d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 071a3ef 6.3.4