Problem with libomp (was supertux)

[Ken Cunningham]

> On Dec 5, 2020, at 11:21 AM, Eric Borisch <eborisch at macports.org> wrote:
> 
> We could:
> 
>  * leave the current patch applied to clang-* (to teach clang where to get the library if it is installed)
>  * make clang-* no longer depend upon libomp
>  * Add a post-install note of "to enable OpenMP support, install libomp"
>  * Have libomp depends_build upon the latest clang on the platform (is there an automagic way to do this?)
> 
> For most (standard install; many pre-compiled binaries) users, libomp would be installed via pre-built packages, and wouldn't have to pull down clang to build it.
> 
> This would also avoid having multiple libomp instances on the system, which seems like a "good thing".
> 
> How does that sound? I like having 'sudo port install clang-X' yield a fully featured (-fopenmp just works) compiler, but a reminder note and simple "sudo port install libomp" isn't all bad...
> 
>   - Eric

From a practical point of view great.

But requiring the manual step to get libomp will never be acceptable to MacPorts, as it is buildbot-unfriendly and breaks the reproducible builds model.

So we just (I think…) have to have the Portfile addition

compiler.omp-required 4.5  

(or whatever the command is) also mandate a lilb dep on "port:libomp”.

Sounds trivial, and gets it out of the clang/llvm tree.


Ken