$ git clone -n https://src.fedoraproject.org/rpms/plasma-welcome-fedora.git /var/lib/mock/f42-build-3426601-45197/root/chroot_tmpdir/scmroot/plasma-welcome-fedora
Cloning into '/var/lib/mock/f42-build-3426601-45197/root/chroot_tmpdir/scmroot/plasma-welcome-fedora'...
$ git fetch origin 589537f8bedcc835dc605f4eaae506f6ef85929b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-welcome-fedora
 * [new ref]         589537f8bedcc835dc605f4eaae506f6ef85929b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 589537f 6.3.3