Updating lang/ocaml

[Jaap Boender <jaapb%kerguelen.org@localhost>]

Hi list,

I'm working on updating lang/ocaml to version 4.14 (in alpha at the 
moment - I'm working in wip so far), and with this update I'd like to 
change the way that the package determines when to build its native 
compiler and other stuff, in order to get rid of the cumbersome 
conditionals in lang/ocaml/Makefile and mk/ocaml.mk, or at least 
concentrate them in one place.

My idea was to have one option (ocaml-native) that has a default value 
determined by whether the architecture supports the native code 
compiler, which is then interpreted by all the ocaml packages (through 
mk/ocaml.mk) to build/use the native compiler or not.

My first interpretation of section 16.4 of the pkgsrc guide (dealing 
with pkg-build-options.mk) was that this was the way to do it: in 
ocaml.mk we could check if lang/ocaml had the ocaml-native option set, 
and act accordingly. But this doesn't seem to work, since if I try this 
out in ocaml.mk I get the message that pkg-build-options can only be 
included in a buildlink3.mk file.

So I'm now thinking of just having an ocaml-native global option that 
gets checked by every ocaml package (and the compiler) separately. It's 
not completely fool-proof, since if you change that option you'd have to 
delete and rebuild all your ocaml packages, but it's doable.

I now have three questions for the collective wisdom of tech-pkg@ to 
consider:

- can this be done more elegantly?

- how can I set a default value for an option globally, rather than in 
one specific options.mk?

- can I use the options.mk framework in mk files?

I'd be grateful for any advice.

best,

  Jaap