Merge pull request #2597 from firedrakeproject/fix_doc_build

Work around the issue raised in: actions/checkout#956 by setting the container user to root. Note that we don't want to do this more generally due to the configuration we use on the self-hosted builders.

Author: dham

.github/workflows/docs.yml

@@ -17,17 +17,10 @@ jobs:
     # The docker container to use.
     container:
       image: firedrakeproject/firedrake-vanilla:latest
+      options: --user root
     # Steps represent a sequence of tasks that will be executed as
     # part of the jobs
     steps:
-      - name: Fix permissions
-        # Firedrake's Dockerfile sets USER to firedrake instead of
-        # using the default user, so we need to update file
-        # permissions for this image to work on GH Actions.
-        # See https://help.github.com/en/actions/reference/virtual-environments-for-github-hosted-runners#docker-container-filesystem
-        # (copied from https://help.github.com/en/actions/migrating-to-github-actions/migrating-from-circleci-to-github-actions)
-        run: |
-          sudo chmod -R 777 $GITHUB_WORKSPACE /github /__w/_temp
       - uses: actions/checkout@v2
       - name: Install
         run: |