$ git clone -n https://src.fedoraproject.org/rpms/rust-bootupd.git /var/lib/mock/f40-build-2654995-66909/root/chroot_tmpdir/scmroot/rust-bootupd
Cloning into '/var/lib/mock/f40-build-2654995-66909/root/chroot_tmpdir/scmroot/rust-bootupd'...
$ git fetch origin cb68445e56bcb0af9291c3f4773a6359a05d22a3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bootupd
 * [new ref]         cb68445e56bcb0af9291c3f4773a6359a05d22a3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cb68445 backport patch to support GRUB console.cfg