$ git clone -n https://src.fedoraproject.org/rpms/keyutils.git /var/lib/mock/f40-build-2005647-45096/root/chroot_tmpdir/scmroot/keyutils
Cloning into '/var/lib/mock/f40-build-2005647-45096/root/chroot_tmpdir/scmroot/keyutils'...
$ git fetch origin 2645b1fdacb50373fcbd73f7d58e27c854eab9c1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/keyutils
 * [new ref]         2645b1fdacb50373fcbd73f7d58e27c854eab9c1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2645b1f Update to v1.6.3