add ipywidgets dependency to doc group. Add options for docs session.

.gitlab-ci.yml

@@ -310,7 +310,7 @@ build-documentation:
   stage: docs
   needs: []
   script:
-    - nox --session docs
+    - nox --session docs -- --fail-on-warnings
   tags:
     - docker
     - cuda11

noxfile.py

@@ -54,7 +54,7 @@ def install_cupy(
 def check_external_doc_dependencies(session: nox.Session):
     dot_args = ["dot", "--version"]
     try:
-        _ = subprocess.run(dot_args)
+        _ = subprocess.run(dot_args, capture_output=True)
     except FileNotFoundError:
         session.error(
             "Unable to build documentation: "
@@ -119,5 +119,16 @@ def docs(session: nox.Session):
     check_external_doc_dependencies(session)
     install_cupy(session, "12.3")
     editable_install(session, ["doc"])
+
+    env = {}
+
+    session_args = session.posargs
+    if "--fail-on-warnings" in session_args:
+        env["SPHINXOPTS"] = "-W --keep-going"
+
     session.chdir("docs")
-    session.run("make", "html", external=True, env={"SPHINXOPTS": "-W --keep-going"})
+
+    if "--clean" in session_args:
+        session.run("make", "clean", external=True)
+
+    session.run("make", "html", external=True, env=env)

pyproject.toml

@@ -59,6 +59,7 @@ doc = [
     'sphinx_design',
     'myst-nb',
     'matplotlib',
+    'ipywidgets',
     'graphviz',
 ]
 testsuite = [