doc/Makefile: turn warnings into errors

Several patches delivered incorrect restructured text as documentation. We
should be able to discover this in Travis CI, Gitlab CI, or Azure CI.

So let us turn all build warnings into errors.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/doc/Makefile b/doc/Makefile
index 5135a96e88d7897a5eb03f46dc0f8ddee3e6c919..0e0da5666f825b8874b788a1848875045d0d5e6d 100644 (file)
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -56,6 +56,7 @@ quiet_cmd_sphinx = SPHINX  $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
        PYTHONDONTWRITEBYTECODE=1 \
        BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \
        $(SPHINXBUILD) \
+       -W \
        -b $2 \
        -c $(abspath $(srctree)/$(src)) \
        -d $(abspath $(BUILDDIR)/.doctrees/$3) \