$ git clone -n https://src.fedoraproject.org/rpms/rabbitmq-server.git /var/lib/mock/f45-build-34269-683/root/chroot_tmpdir/scmroot/rabbitmq-server
Cloning into '/var/lib/mock/f45-build-34269-683/root/chroot_tmpdir/scmroot/rabbitmq-server'...
$ git fetch origin 5e7c0db2c1c054d1abc4e77a555e63ceb3381353:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rabbitmq-server
 * [new ref]         5e7c0db2c1c054d1abc4e77a555e63ceb3381353 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5e7c0db RabbitMQ ver. 4.3.6