cpp /usr/include/threads.h fails; modfl segfaults

[Ken Brown]

On 8/29/2020 9:21 PM, airplanemath via Cygwin wrote:
> Stepping back through Cygwin releases, I find:
> 
> $ gcc -Og -ggdb -g3 -Wall -Wextra -std=c99 -pedantic test.c -o test.exe
> 
> $ ./test.exe 123.456
> 123.456000 0.456000 123.000000
> 
> $ uname -a | sed "s/${HOSTNAME}/\${HOSTNAME}/g"
> CYGWIN_NT-10.0 ${HOSTNAME} 3.1.4(0.340/5/3) 2020-02-19 08:49 x86_64 Cygwin
> 
> $ gcc --version
> gcc (GCC) 9.3.0
> Copyright (C) 2019 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.� There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> 
> 
> 3.1.5 crashed the same way as 3.1.7.� There's nothing obvious in the
> 3.1.5 announcement [1],
> so I'm stuck again.

OK, so the problem was introduced between 3.1.4 and 3.1.5.  It should be pretty 
easy to bisect and find the culprit.  I'll do that tomorrow if no one beats me 
to it.

Ken