$ git clone -n https://src.fedoraproject.org/rpms/rust-gdk4-sys0.6.git /var/lib/mock/f40-build-2656705-66915/root/chroot_tmpdir/scmroot/rust-gdk4-sys0.6
Cloning into '/var/lib/mock/f40-build-2656705-66915/root/chroot_tmpdir/scmroot/rust-gdk4-sys0.6'...
$ git fetch origin b213911b271c2a24af5df8773eab60f7b26b3d9f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gdk4-sys0.6
 * [new ref]         b213911b271c2a24af5df8773eab60f7b26b3d9f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b213911 compat package no longer needed