$ git clone -n https://src.fedoraproject.org/rpms/rust-minus.git /var/lib/mock/f40-build-2718622-72942/root/chroot_tmpdir/scmroot/rust-minus
Cloning into '/var/lib/mock/f40-build-2718622-72942/root/chroot_tmpdir/scmroot/rust-minus'...
$ git fetch origin 4dc49b93d0c3ab30ec7ddf85b0fdba11fd652d8c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-minus
 * [new ref]         4dc49b93d0c3ab30ec7ddf85b0fdba11fd652d8c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4dc49b9 Update to version 5.6.1; Fixes RHBZ#2269026