Re: errno in gdb

[Jim Meyering]

Bruno Haible <address@hidden> wrote:
> Jim Meyering wrote:
>> I did not set errno, which would normally happen for a real failure.
>> I tried, but __errno_location() returns an invalid address.
>> Anyone know how to set errno via gdb?
>
> I normally use
>   (gdb) print errno = 22
> since in a single-threaded situation __errno_location() == &errno.

Thanks, but that was the first thing I tried.
It doesn't work on rawhide:

  (gdb) p errno = 2
  TLS symbol `errno' not resolved for non-TLS program. You should use symbol 
"(*__errno_location ())" or compile the program with `gcc -ggdb3' or `gcc 
-pthread'.
  (gdb)

nor with the tools in debian unstable:

  (gdb) p errno = 1
  No symbol "errno" in current context.

Using -ggdb3 didn't help, but finally when I took the 2nd suggestion
and compiled with -pthread, I could set errno (to ENOMEM=12).

Same result: segfault.