[master] bbc94c1c7 Add missing sphinx-build make dependencies

[Dridi Boukelmoune]

commit bbc94c1c7a40d3d82f4d88be8ce39794f1237d9f
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Wed Jun 10 17:17:50 2020 +0200

    Add missing sphinx-build make dependencies
    
    At this point I'm wondering whether we should talk about hacks when we
    really add missing dependencies. In some cases it boils down to RST
    being generated by programs we need to compile, what I call "regular"
    targets here.

diff --git a/Makefile.am b/Makefile.am
index a48e06819..f0e132389 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -56,6 +56,10 @@ LICENSE: all
 # before we try to run tests anywhere in the tree.
 check-recursive: all
 
+# XXX: This is the exact same hack since some parts of the documentation
+# are generated as regular targets but needed by the html special target.
+html-recursive: all
+
 cscope:
 	-rm -f cscope*
 	find . -name '*.[hcS]' > cscope.files