On 9/29/2021 7:46 PM, Brian Inglis wrote:
There is a gnulib bug in threadlib.m4 from at least serial 29 to serial
31 that incorrectly configures Cygwin support of weak references.
This leads to SIGSEGV stack smashing crashes with no backtrace
@ 0x00000000100000000 or 0x0000000500000000 etc. normally during tests.
Akim Demaille on bug-bison referred the issue to bug-gnulib where
Bruno Haible diagnosed and patched the problem to appear in
m4/threadlib.m4 serial 32:
* m4/threadlib.m4 (gl_WEAK_SYMBOLS): Force a "guessing no" result on Cygwin
https://lists.gnu.org/archive/html/bug-gnulib/2021-09/msg00068.html
[gl_cv_have_weak="guessing no"]
The patch has now been applied to bison, wget, and wget2, and I have
attached my patches for the copies in those packages, in case anyone
else has this issue in their (mainly GNU) packages which may incorporate by
inclusion recently updated gnulib m4 macros used in autotools builds.
Thanks, Brian.
I'm writing to reinforce this warning. I just spent 2 days trying to debug
mysterious texinfo crashes that were caused by this bug. I could have saved a
lot of time if I had remembered your email and had checked the gnulib version
being used by texinfo.
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.
Ken
