depends_build port:doxygen and +universal (or +docs)

[Lawrence Velázquez]

> On Sep 22, 2016, at 9:07 AM, René J.V. Bertin <rjvbertin at gmail.com> wrote:
> 
> Is there a way to stop certain variants from propagating to dependencies?

I'm pretty sure there is no way to do this. No clean way, at least.

> I'd like to use `depends_build-append port:doxygen` for +docs variants, but
> 
> - calling the variant +docs causes port:doxygen to install (or reinstalll!) with +docs, which adds lots of dependencies, and big ones at that (TeX)

Perhaps doxygen should be split up into doxygen and doxygen-docs subports to avoid this kind of thing.

> - if the target port is requested +universal this also causes doxygen to be (re)installed with +universal, which again isn't necessary at all.

If the dependent just invokes doxygen, then it can use

	depends_skip_archcheck-append doxygen

I don't know if doxygen itself installs any libraries or headers; if not, it should use

	installs_libs no

so that dependents don't have to use depends_skip_archcheck.

vq