Turns out automake doesn't like either that we add dependencies to a
target conditionally. Not sure why, but it's a tasteless thing to do
nevertheless:
gtk-doc.make:174: warning: $(DOC_MAIN_SGML_FILE) was already defined in condition BUILD_DOCS, which is included in condition TRUE ...
docs/api/Makefile.am:112: 'gtk-doc.make' included from here
docs/api/Makefile.am:14: ... '$(DOC_MAIN_SGML_FILE)' previously defined here
In any case, the dependency is wrong in the first place -- the source
document doesn't depend on other source. The target (which is a stamp
file, since the xslt processor produces multiple files) does! Moreover,
there's a dependency of the stamp file on $(content_files) already, so
including GENERATED_FILES (like we already do) in content_files should
be sufficient.
While at that, deal with other not-so-nice things; don't extend "all"
target needlessly and don't define a target conditionally.
4c49d67cc8