Re: pkgsrc gcc discussion #3874

[David Holland <dholland-pkgtech%netbsd.org@localhost>]

On Sat, Dec 30, 2017 at 08:20:13PM -0500, Greg Troxel wrote:
 > The logic for how we have to end up at a single version is in
 >   https://wiki.netbsd.org/pkgsrc/gcc/
 > If you can spot a flaw, please point it out.

See what I just posted in the earlier thread: this doesn't actually
solve the non-local-reasoning problem, just makes it global. There's
no way for a user to decide what to set PKGSRC_GCC_VERSION or
PKGSRC_GXX_VERSION to based on the packages they want to build, other
than looking through everything by hand or via trial and error.

This is not a trivial issue because on a small or slow system running
an older OS build (say, -7) large numbers of packages will still build
fine with the existing compiler, and having to build gcc again is a
showstopper.

The non-local reasoning problem is Hard and maybe we can't solve it,
but if we're going to have a global setting we do need a way for users
to discover how to set it. Maybe the way to do this is to provide a
make target to report if a package won't work with a given setting,
and run this on the whole pkgsrc tree and post the results on the web
page.

In any event, we also need a way to reject bad combinations at build
time, as we can't rely on the shared library system to do this; we'll
end up creating broken executables that will run but summon nasal
demons.

(then there's the question of how to bootstrap gcc safely...)

-- 
David A. Holland
dholland%netbsd.org@localhost