$ git clone -n https://src.fedoraproject.org/rpms/rust-vec1.git /var/lib/mock/f38-build-side-42-init-devel-775997-27806/root/chroot_tmpdir/scmroot/rust-vec1
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-775997-27806/root/chroot_tmpdir/scmroot/rust-vec1'...
$ git fetch origin 741bb2978012a59392c97080f326f0b08c3c657c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-vec1
 * [new ref]         741bb2978012a59392c97080f326f0b08c3c657c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 741bb29 Added the README