[tlbuild] Missing includes for zlib when building woff2 (dvisvgm)

[Mojca Miklavec]

Dear Karl,

On Tue, 26 Mar 2019 at 23:35, Karl Berry wrote:
>
>     mg> append $(ZLIB_INCLUDES) to AM_CFLAGS in file libs/ff-woff/Makefile.am?
>
> I committed this to TL (r50610). Thanks.

Thank you for the changes.

When I skip building xetex the TL now cross-compiles out of the box.

>     Maybe TeX Live could populate the ZLIB_CFLAGS variable? I don't know
>     what's the most generic / standard way to specify flags in such cases.
>
> There is no standard way. peb set everything up to use the
> <lib>_INCLUDES and <lib>_LIBS variables. Somehow it would seem more
> confusing than helpful to me to define both. -k

The only other thing that would be nice would be to patch dvisvgm
upstream to make this work automatically. I was just thinking aloud
about what one could do in a reasonable way, since upstream doesn't
know about TeX Live's own macros placed in top directories.

Thanks to both,
    Mojca