Problem with running simple pthreads program under gdb-7.2 (Invalid selected thread)

[Raphael Kubo da Costa]

Dmitry Krivenok <krivenok.dmitry at gmail.com> writes:

> As you can see program exited normally w/o any errors.
> Then I run the same program under gdb-7.2
>
> $ /usr/local/bin/gdb72 --args t
> GNU gdb (GDB) 7.2 [GDB v7.2 for FreeBSD]
> Copyright (C) 2010 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-portbld-freebsd8.2".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> Reading symbols from /big/work/coverage/csxroot/src/t/t...done.
> (gdb) r
> Starting program: /big/work/coverage/csxroot/src/t/t
> [New LWP 100162]
> [New Thread 800a041c0 (LWP 100162)]
> [New Thread 800a0ae40 (LWP 100171)]
> [Thread 800a0ae40 (LWP 100171) exited]
> Invalid selected thread.
> (gdb) q
> A debugging session is active.
>
>        Inferior 1 [process 7756] will be killed.
>
> Quit anyway? (y or n) y
> $
>
> In this case I got "Invalid selected thread." right after the thread has exited.
> Looks like gdb is unable to switch to another thread.

In my case, I get the following error when running your program (and
many others) with the gdb72 package (installed via portmaster -PP
devel/gdb):

(gdb) r
Starting program: /tmp/test-base
[New LWP 100315]
Cannot get thread info, Thread ID=100315, generic error
(gdb) q
A debugging session is active.

        Inferior 1 [process 84832] will be killed.

Quit anyway? (y or n) y

If I compile the port myself, I can't run any binary (PR ports/152896,
which has been unanswered despite my efforts):

  Reading symbols from /usr/local/bin/gdb72...I'm sorry, Dave, I can't
  do that.  Symbol format `elf64-x86-64-freebsd' unknown.

This is 8.2-STABLE.