Re: how to mark llvm* forbidden?

On Thu, 6 Apr 2017 17:26:18 +0000, Brooks Davis <brooks_at_freebsd.org> wrote:

> On Wed, Apr 05, 2017 at 06:18:37PM -0700, Russell L. Carter wrote:
> > On 04/05/17 15:32, Chris H wrote:
> > > On Wed, 5 Apr 2017 21:51:40 +0000 Brooks Davis <brooks_at_freebsd.org> wrote
> > > 
> > >> On Wed, Apr 05, 2017 at 11:42:16AM -0700, Chris H wrote:
> > >>> OK I'm chasing -CURRENT, and I performed an initial
> > >>> install, followed by a new world/kernel && ports about a
> > >>> mos ago. Last Friday, I svn upped the system (src && ports),
> > >>> rebuilt/installed world/kernel. I just began rebuilding
> > >>> the ports, only to find that when finished, I will likely
> > >>> end up with every version of llvm && clang from version 3
> > >>> to the now current 4. My build session is currently tying
> > >>> nearly every core on the CPU with llvm builds. Given that
> > >>> llvm4 comes in base. Is there *any* reason I can not insist
> > >>> that the ports I upgrade, or build, just use the version(s)
> > >>> of clang/llvm in base? If so. How do I inform the ports
> > >>> that they may *only* use the version(s) in base?
> > >>
> > >> In general you can't.  There are many reasons including: the base llvm
> > >> doesn't include the requisite cmake bits for cmake based ports, some
> > >> ports use unstable APIs and require specific LLVM versions, and some use
> > >> LLVM tools or libraries that aren't built/installed as part of the base
> > >> system.
> > >>
> > >> There are probably some ports where the base clang is fine but that's
> > >> probably mostly down to someone getting USES variables right.
> > >>
> > >> -- Brooks
> > > Grumble.. That's what I was afraid I might hear.
> > > 
> > > Thanks, Brooks! Even if it's not what I was hoping to hear. :)
> > 
> > FWIW, this is biting me hard right now too.  I feel your
> > pain...  I'm a c++17 junky but I might have to let go of
> > llvm-devel.
> 
> If you want to track clang development, I would generally dis-recommend
> the llvm-devel port.  If you check out from upstream svn/git and build
> with cmake and ninja, then you get pretty efficient incremental builds.
> One nice think about the llvm build infrastructure is that you can use
> it in place in the build's bin directory so you don't even need to
> maintain an installed copy.
> 
> -- Brooks


Can/should this be in /usr/ports/UPDATING?