$ git clone -n https://src.fedoraproject.org/rpms/php-guzzlehttp-promises.git /var/lib/mock/f45-build-27900-626/root/chroot_tmpdir/scmroot/php-guzzlehttp-promises
Cloning into '/var/lib/mock/f45-build-27900-626/root/chroot_tmpdir/scmroot/php-guzzlehttp-promises'...
$ git fetch origin b959f3e257b8840b839c94993d85278a63ab76a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/php-guzzlehttp-promises
 * [new ref]         b959f3e257b8840b839c94993d85278a63ab76a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b959f3e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild