$ git clone -n https://src.fedoraproject.org/rpms/rubygem-rspec-expectations.git /var/lib/mock/f40-build-2639318-66352/root/chroot_tmpdir/scmroot/rubygem-rspec-expectations
Cloning into '/var/lib/mock/f40-build-2639318-66352/root/chroot_tmpdir/scmroot/rubygem-rspec-expectations'...
$ git fetch origin cfa15bf1506dca52b5795759ca6d4759ba971680:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-rspec-expectations
 * [new ref]         cfa15bf1506dca52b5795759ca6d4759ba971680 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cfa15bf enable test again