fix docs build

Author: parthea

noxfile.py

@@ -217,7 +217,20 @@ def docs(session):
     """Build the docs for this library."""
 
     session.install("-e", ".[grpc]")
-    session.install("sphinx==4.2.0", "alabaster", "recommonmark")
+    session.install(
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
+        "sphinx==4.5.0",
+        "alabaster",
+        "recommonmark",
+    )
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)
     session.run(
@@ -240,7 +253,18 @@ def docfx(session):
 
     session.install("-e", ".")
     session.install(
-        "sphinx==4.0.1", "alabaster", "recommonmark", "gcp-sphinx-docfx-yaml"
+        # We need to pin to specific versions of the `sphinxcontrib-*` packages
+        # which still support sphinx 4.x.
+        # See https://github.com/googleapis/sphinx-docfx-yaml/issues/344
+        # and https://github.com/googleapis/sphinx-docfx-yaml/issues/345.
+        "sphinxcontrib-applehelp==1.0.4",
+        "sphinxcontrib-devhelp==1.0.2",
+        "sphinxcontrib-htmlhelp==2.0.1",
+        "sphinxcontrib-qthelp==1.0.3",
+        "sphinxcontrib-serializinghtml==1.1.5",
+        "gcp-sphinx-docfx-yaml",
+        "alabaster",
+        "recommonmark",
     )
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)