[Bug target/90330] gcc 9.1.0 fails to install on macOS 10.14.4

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90330

--- Comment #9 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Matt Thompson from comment #8)
> (In reply to Iain Sandoe from comment #7)
> > (In reply to Matt Thompson from comment #6)
> > > (In reply to Iain Sandoe from comment #5)
> > > > (In reply to Matt Thompson from comment #4)
> > > > > Also: I do have all the log files still, so if you'd like anything grep'ed
> > > > > in there, let me know.
> > > > 
> > > > not at this time.. I am trying to figure out what is different about our
> > > > configurations.
> > > > 
> > > > ---
> > > > 
> > > > can you confirm that this was a clean build (including that the target
> > > > install directory was deleted before the build?)
> > > 
> > > It was a clean build. I always build out-of-source so it was a new directory
> > > and I'd never installed GCC 9.1.0 before, so the install directory was new
> > > as well.
> > > 
> > > Let me try building again in a new directory with a new install location. Of
> > > course, being the impressive GCC build, it might be Monday before I can
> > > report back (it's a work laptop that stays at work).
> > 
> > OK thanks, as it happens I won't be able to try on Darwin18 before next
> > Weds, so no hurry.
> 
> I just tried to rebuild gcc 9.1.0 on my laptop, and I got the same error at
> the same point in make install.

One possible (although I suspect unlikely) issue is a race condition when
instslling symlinks which is known to occur on AFPS (the system I use for
testing is HHFS+).

does it reliably still fail if you try to restart the install?

> I'll try a few other experiments (remove /usr/local/bin from my path in case
> brew is causing an issue, though it didn't before).

OK - when I build toolchains the environment has no macports/fink/homebrew
content so there's no possibility of interaction.
>

> Or should I be using one of my other compilers to build gcc? 

I have built with both clang (10.2 command line tools) and a toolchain based on
GCC 8.3 (although not a formal release) - both builds succeeded - I have no
access to my Darwin18 system right now, so not able to attempt to repeat your
exercise.

Presumably, the 8.2 toolchains is correctly installed and has not been moved,
so that the shared libraries from that are on the correct paths (the kind of
error you are seeing could be the wrong dylib being found).

If you can find the exact command line that fails and repeat it, prepended by
DYLD_PRINT_LIBRARIES=1, that will show you which dylibs are loaded as the
command tries to execute (there might be quite a lot of output, so not
necessarily easy to interpret)

I have built
> gcc 8.2.0. Instead of using clang, I could try that...though I'm not sure
> how. Just pass in CC and CXX to configure?

yes, and/or make sure that the GCC toolchain bin dir is before the system ones
in your path.