textproc/hs-pandoc: Fix build and remove run-time dependency on ghc

[jrm]

Summary

Also:

• simplify options
• binary is linked to libffi.so, so add LIB_DEPENDS on devel/libffi
• pacify portlint

TODO: Add revision before committing

PR:
Submitted by:
Reported by:

Test Plan

poudriere testport for 12amd64 with different option combinations passes. I will test 11 i386/amd64 and 12i386 over night.

[adamw]

It installs the package in 4 seconds. This is all I ever wanted in this world.

[jrm]

This needs more work. A bunch of .hi are being installed under /usr/local/lib/cabal/ghc-8.6.3/. Something like the Debian pandoc package, which has minimal dependencies and essentially just installs a 70 MB binary, would be nice. Although, their package is for quite an old version of pandoc. The Arch package also seems reasonable. The binary is small and the package only depends on the shared libraries, but not ghc.

[arrowd]

Tried this out on rel12x86, works nice.

You can easily prevent *.hi files from being installed by adding post-install rule that runs something like find ${STAGEDIR} -name '*.hi' -delete.

[jrm]

On closer inspection, it might be reasonable to have these .hi files installed. They are not large and if my guess is correct, they are for other applications linking with libHSpandoc-2.5-???.a. Thoughts?

[arrowd]

Are you going to commit this, or want me to do that?

[jrm]

I'll commit today.