$ git clone -n https://src.fedoraproject.org/rpms/rust-directories3.git /var/lib/mock/f42-build-side-1-3589325-46957/root/chroot_tmpdir/scmroot/rust-directories3
Cloning into '/var/lib/mock/f42-build-side-1-3589325-46957/root/chroot_tmpdir/scmroot/rust-directories3'...
$ git fetch origin 7feaf6413369cf331a4ee03d285c1d04a1f3048d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-directories3
 * [new ref]         7feaf6413369cf331a4ee03d285c1d04a1f3048d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7feaf64 compat package no longer needed