Re: graphics/ImageMagick: make dependencies optional

[Greg Troxel <gdt%lexort.com@localhost>]

nia <nia%netbsd.org@localhost> writes:

> I wanted to disable tiff and ghostscript support in ImageMagick so I
> wouldn't need those libraries on my server, so I made them and the
> other ImageMagick dependencies optional.
>
> The resulting binaries seem to work and don't depend on dynamic libraries
> from any disabled dependencies. It seems to work with ghostscript
> uninstalled, despite the comment hinting otherwise. Actually, building
> with _all_ of these dependencies disabled still seems to work, and
> `readelf -d` produces expected results.

The big question here is the value vs the complexity.  Dropping a
particularly big dependency that many won't want seems good compared to
the maintenance pain of adding an option.  Dropping tiff which isn't
that big (3M) while keeping ImageMagick (28M just for the package,
double that currently) is hard for me to see the value of, for systems
which are doing image processing in the first place.

Of course there are shades of grey.  Getting rid of djvu (I'm not even
sure what that is) seems far more useful than png (have we identified a
single person that wants ImageMagick but wants the system not to have
libpng??).  Plus dropping bzip2 seems strange to me.

So I'm in favor of adding the ghostscript option, against png/bzip2
options (absent rationale), and just barely against tiff.

I'm against a strategy of optionizing every library, and instead for
optionizing those that are both heavyweight and for which we think
significant numbers of people would want to avoid.

Note that I'm not the ImageMagick maintainer, so this is just another
opinion.

> It was my intention to bmake the default option set identical to the
> implied set of the original, so things wouldn't break.

Good -- that is the way we do it.