$ git clone -n https://src.fedoraproject.org/rpms/rubygem-websocket-extensions.git /var/lib/mock/f45-build-35395-695/root/chroot_tmpdir/scmroot/rubygem-websocket-extensions
Cloning into '/var/lib/mock/f45-build-35395-695/root/chroot_tmpdir/scmroot/rubygem-websocket-extensions'...
$ git fetch origin e56133b6a0a81aa2d255e9db0d6eae0ead28dd3c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-websocket-extensions
 * [new ref]         e56133b6a0a81aa2d255e9db0d6eae0ead28dd3c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e56133b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild