gnulib m4/threadlib.m4 bug crashing package tests

[Ken Brown]

On 11/28/2021 10:42 AM, Achim Gratz wrote:
> Yaakov Selkowitz via Cygwin-apps writes:
>>> For anyone else who bumps into this, gdb and strace are of no use in
>>> debugging this crash.  I finally thought to look at the stackdump
>>> file, and the second address from the top was in a gnulib file.  That
>>> was the key clue.
>>
>> Add gl_cv_have_weak=no to cygconf?
> 
> I'd rather know why the bleeping heck the test suddenly succeeds when it
> clearly doesn't actually work.  In other words, I think the linker
> should complain, but since it obviously did that before Cygwin 3.2.0 and
> not after, something must have changed somewhere that prevent s it from
> doing that.

It's gnulib that changed, not Cygwin or gcc/binutils.  This is actually an old 
issue:

   https://cygwin.com/pipermail/cygwin/2010-April/186342.html

Ken