As per title, (not so) longer traceback is:
Initiated sphinxcontrib-images backend: `sphinxcontrib_images_lightbox2.lightbox2:LightBox2` building [mo]: targets for 0 po files that are out of date building [html]: targets for 522 source files that are out of date updating environment: [new config] 522 added, 0 changed, 0 removed reading sources... [ 0%] apidoc/modules reading sources... [ 0%] apidoc/swh reading sources... [ 0%] apidoc/swh.core reading sources... [ 0%] apidoc/swh.core.api Exception occurred: File "/home/jenkins/workspace/DDOC/publish/swh-docs/.tox/sphinx/lib/python3.7/site-packages/flask/globals.py", line 38, in _lookup_req_object raise RuntimeError(_request_ctx_err_msg) RuntimeError: Working outside of request context. This typically means that you attempted to use functionality that needed an active HTTP request. Consult the documentation on testing for information about how to avoid this problem. The full traceback has been saved in /tmp/sphinx-err-pof5su3o.log, if you want to report the issue to the developers.
Full build log: https://jenkins.softwareheritage.org/job/DDOC/job/publish/543/console