bin/52086: cannot debug firefox with gdb

[scole_mail%gmx.com@localhost]

>Number:         52086
>Category:       bin
>Synopsis:       cannot debug firefox with gdb
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 17 16:50:00 +0000 2017
>Originator:     scole_mail
>Release:        NetBSD 7.1.0 pkgsrc-2016Q4
>Organization:
none
>Environment:
NetBSD dstar 7.1.0_PATCH NetBSD 7.1.0_PATCH (GENERIC) #0: Wed Mar 15 10:13:06 PDT 2017  scole@dstar:/home/scole/nbsd/cvs/7_0/obj/sys/arch/i386/compile/GENERIC i386
>Description:
martin asked me to submit a PR for this, he thinks it may be a ld.elf_so or gdb issue.

I was trying to debug firefox crashes with the method outlined in 
  http://wiki.netbsd.org/tutorials/pkgsrc/debugging_firefox/
I was building with these options

bmake PKG_DEFAULT_OPTIONS="alsa dbus debug-info" ALLOW_VULNERABLE_PACKAGES=1

and ran 
 run-mozilla.sh -g ./firefox
from the directory described in the tutorial link.

I would immediately get a SIGTRAP and couldn't read any vars in gdb

scole@dstar:/usr/pkgsrc/www/firefox/work/build/dist/bin> ./run-mozilla.sh -g ./firefox
MOZILLA_FIVE_HOME=.
  LD_LIBRARY_PATH=.:./plugins:.
DISPLAY=:0
DYLD_LIBRARY_PATH=.:.
     LIBRARY_PATH=
       SHLIB_PATH=.:.
          LIBPATH=.:.
       ADDON_PATH=
      MOZ_PROGRAM=./firefox
      MOZ_TOOLKIT=
        moz_debug=1
     moz_debugger=
moz_debugger_args=
/usr/bin/gdb  --args ./firefox
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Reading symbols from ./firefox...done.
.gdbinit:183: Error in sourced command file:
gdbpp:5: Error in sourced command file:
Python scripting is not supported in this copy of GDB.
(gdb) run
Starting program: /usr/pkgsrc/www/firefox/work/build/dist/bin/firefox 

Program received signal SIGTRAP, Trace/breakpoint trap.
0xbb572937 in ?? ()
(gdb) list
315         rv = NS_NewNativeLocalFile(nsDependentCString(exePath), false,
316                                    xreDirectory);
317     #endif
318       }
319     
320       return rv;
321     }
322     
323     int main(int argc, char* argv[], char* envp[])
324     {

>How-To-Repeat:
See description
>Fix:
?