Hack around sphinx_immaterial download issues

.circleci/config.yml

@@ -391,6 +391,15 @@ jobs:
       - restore_cache:
           keys: v1-docs-cache
 
+      # Sphinx_immaterial does parallel downloads that don't work
+      # well on CircleCI. There is no setting, so we just edit
+      # the max number of workers. Bit gross, but this isn't our
+      # production doc build anyways, that happens on RTD without hacks.
+      - run:
+          name: hack sphinx_immaterial
+          command: |
+            sed -i 's/max_workers=32/max_workers=1/' /mnt/ramdisk/venv/lib/py*/site-packages/sphinx_immaterial/google_fonts.py
+
       - run:
           name: build docs
           command: |