📝 Establish redirects #7162

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1. adoodevv commented on Oct 10, 2026

   

   adoodevv

   on Oct 10, 2026

   More actions

   I looked into this. Many of the old URLs already have .. redirect-from:: entries, but the redirect pages are no longer being generated.

   For example, source/ROS-Framework/About-Client-Libraries.rst still declares:

   .. redirect-from::
   
      Concepts/About-Client-Interfaces
      Concepts/About-ROS-2-Client-Libraries
      Concepts/Basic/About-Client-Libraries

   But on the live site:

   URL	Status
   https://docs.ros.org/en/rolling/Concepts/Basic/About-Client-Libraries.html	404
   https://docs.ros.org/en/jazzy/Concepts/Basic/About-Client-Libraries.html	200
   https://docs.ros.org/en/rolling/ROS-Framework/About-Client-Libraries.html	200

   Root cause

   Since #7021, the build runs with -j auto. RedirectFrom in conf.py collects redirects in a class attribute, RedirectFrom.redirections, during the read phase. With parallel reads, that attribute is filled in inside the worker processes and never merged back into the main process. As a result, the html-collect-pages handler sees an empty dict and writes no redirect pages.

   Locally, on current rolling:

   • make html (parallel) generates 0 redirect pages
   • make html JOBS=1 generates 477 redirect pages

   Proposed fix

   Store the redirections on the Sphinx build environment instead of on the class, merge them back from the parallel readers with the env-merge-info event, and use env-purge-doc so incremental builds stay correct. I have a patch for this and will open a PR shortly.
2. adoodevv

   added a commit that references this issue on Oct 14, 2026

   Fix redirect pages not generated in parallel builds

   ...

   This issue will close once commit 3dfc246 is merged into the 'rolling' branch.

   3dfc246