$ git clone -n https://src.fedoraproject.org/rpms/rust-sval_ref.git /var/lib/mock/f41-build-side-1-3134926-39764/root/chroot_tmpdir/scmroot/rust-sval_ref
Cloning into '/var/lib/mock/f41-build-side-1-3134926-39764/root/chroot_tmpdir/scmroot/rust-sval_ref'...
$ git fetch origin 9136561b05e1db39601bdf0c7707870df320ec07:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-sval_ref
 * [new ref]         9136561b05e1db39601bdf0c7707870df320ec07 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9136561 no longer needed