$ git clone -n https://src.fedoraproject.org/rpms/rust-just.git /var/lib/mock/f40-build-1793976-24862/root/chroot_tmpdir/scmroot/rust-just
Cloning into '/var/lib/mock/f40-build-1793976-24862/root/chroot_tmpdir/scmroot/rust-just'...
$ git fetch origin b31d36fad9389eecec1e7dd7e75fcec81f42a07a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-just
 * [new ref]         b31d36fad9389eecec1e7dd7e75fcec81f42a07a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b31d36f Update to 1.31.0 (#2297872)