On 2021-11-25 11:25, Yaakov Selkowitz via Cygwin-apps wrote:
On Thu, 2021-11-25 at 11:26 -0500, Ken Brown via Cygwin-apps wrote:
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.
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.
Add gl_cv_have_weak=no to cygconf?
or gl_cv_have_weak="guessing no" or
patch [gl_cv_have_weak="guessing no"] above
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in binary units and prefixes, physical quantities in SI.]
