From ff2e64719365e8cda58020850143599f9b91df0c Mon Sep 17 00:00:00 2001
From: Benedikt Fein <fein@fim.uni-passau.de>
Date: Sat, 23 Sep 2023 11:38:09 +0200
Subject: [PATCH] sphinx: treat warnings as errors

---
 docs/.readthedocs.yaml | 2 ++
 docs/Makefile          | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/docs/.readthedocs.yaml b/docs/.readthedocs.yaml
index 1a83fba70835..9522486c382b 100644
--- a/docs/.readthedocs.yaml
+++ b/docs/.readthedocs.yaml
@@ -5,6 +5,8 @@ build:
   os: ubuntu-22.04
   tools:
     python: "3.10"
+sphinx:
+  fail_on_warning: true
 python:
   install:
     - requirements: docs/requirements.txt
diff --git a/docs/Makefile b/docs/Makefile
index 3473b9c8d84f..e7c2e9cec73a 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -3,7 +3,8 @@
 
 # You can set these variables from the command line, and also
 # from the environment for the first two.
-SPHINXOPTS    ?=
+# -W: treat warnings as errors
+SPHINXOPTS    ?= -W
 SPHINXBUILD   ?= sphinx-build
 SOURCEDIR     = .
 BUILDDIR      = _build