doc: Makefile: if sphinx is not found, run a check script

Right now, if the building system doesn't find Sphinx, it
bails out, without providing any instructions about what
should be done.

Instead, run a script, providing some guidance about the
steps needed for Sphinx build to work.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/Makefile b/Documentation/Makefile
index d75c00e3aadb4e27e09ae50e157aa929b0e3aa7b..85f7856f009203d9e7d15487e452a8b9771c3784 100644 (file)
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -22,6 +22,8 @@ ifeq ($(HAVE_SPHINX),0)
 
 .DEFAULT:
        $(warning The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed and in PATH, or set the SPHINXBUILD make variable to point to the full path of the '$(SPHINXBUILD)' executable.)
+       @echo
+       @./scripts/sphinx-pre-install
        @echo "  SKIP    Sphinx $@ target."
 
 else # HAVE_SPHINX