Try with nox

.github/workflows/validate.yml

@@ -21,13 +21,15 @@ jobs:
 
     - name: Build the site in the Jekyll/builder container
       run: |
-        docker run \
-        -v ${{ github.workspace }}:/srv/jekyll -v ${{ github.workspace }}/_site:/srv/jekyll/_site \
-        jekyll/builder:latest /bin/bash -c "chmod -R 777 /srv/jekyll && jekyll build --future"
-        
+        pip install nox
+        nox -s build_no_serve
+
     - name: List result of Jekyll build
       run: ls _site/ -l
 
+    - name: Copy assets
+      run: cp -r assets _site/assets
+
     - name: Publish built site
       uses: actions/upload-artifact@v2
       with:
@@ -70,9 +72,6 @@ jobs:
         name: Built site ${{ github.run_number }}
         path: ./_site
 
-    - name: Copy assets
-      run: cp -r assets _site/assets
-
     # TODO: we are not checking absolute links as pytest plugins does not support them
     - name: Check links
       run: |
@@ -86,8 +85,6 @@ jobs:
     needs: [build]
 
     steps:
-      - name: Fetch repository
-        uses: actions/checkout@v2
       - name: Fetch built site
         uses: actions/download-artifact@v2
         with:

noxfile.py

@@ -16,3 +16,8 @@ def install_deps(session):
 def build(session):
     install_deps(session)
     session.run(*"bundle exec jekyll serve liveserve".split())
+
+@nox.session(venv_backend='conda')
+def build_no_serve(session):
+    install_deps(session)
+    session.run(*"bundle exec jekyll".split())