$ git clone -n https://src.fedoraproject.org/rpms/plasma-welcome.git /var/lib/mock/f41-build-side-1-2753468-31224/root/chroot_tmpdir/scmroot/plasma-welcome
Cloning into '/var/lib/mock/f41-build-side-1-2753468-31224/root/chroot_tmpdir/scmroot/plasma-welcome'...
$ git fetch origin fee2e120f35df881422a3580c43020571271f3d8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-welcome
 * [new ref]         fee2e120f35df881422a3580c43020571271f3d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fee2e12 6.1.90