writing output... [100%] using_tutorial
Warning, treated as error:
/builds/BuildStream/buildstream/dist/buildstream/doc/source/additional_docker.rst:14:undefined label: _docker (if the link has no caption the label must precede a section header)
make: *** [html] Error 2
Makefile:143: recipe for target 'html' failed
make: Leaving directory '/builds/BuildStream/buildstream/dist/buildstream/doc'
section_end:1538793628:build_script
section_start:1538793628:after_script
section_end:1538793629:after_script
section_start:1538793629:upload_artifacts_on_failure
section_end:1538793631:upload_artifacts_on_failure
ERROR: Job failed: exit code 1