$ git clone -n https://src.fedoraproject.org/rpms/rust-bootupd.git /var/lib/mock/f38-build-side-42-init-devel-687974-26769/root/chroot_tmpdir/scmroot/rust-bootupd
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-687974-26769/root/chroot_tmpdir/scmroot/rust-bootupd'...
$ git fetch origin a0f9decb7bdae3d2c80435d217fadbe1551c17b0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bootupd
 * [new ref]         a0f9decb7bdae3d2c80435d217fadbe1551c17b0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a0f9dec Vendor prefix is now in tar