How do I get GDB to break on a GLib assertion failure?

Question

Somewhere in a mass of code that I did not write (but I am trying to debug), an assertion fails in the GLib library:

(process:31987): GLib-CRITICAL **: g_hash_table_lookup: assertion `hash_table != NULL' failed

However, GDB and the code keeps on going. I would like GDB to break where this assertion fails so that I can find out why it is failing. I am not given any more information about where this assertion is. Is there a way to get GDB to break on such a failure?

Duplicate of: http://stackoverflow.com/questions/2450001/how-can-i-find-out-where-is-my-code-causing-glib-gobject-critical but this question is clearer, so I'm voting to close that other one. — ptomato, Apr 26 '11 at 08:13

score 25 · Answer 1 · edited Dec 10 '17 at 16:45

25

You should add an environment variable like this:

G_DEBUG=fatal_warnings gdb ...

edited Dec 10 '17 at 16:45

Peter Mortensen

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answered Nov 07 '11 at 16:14

lovebug356

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`G_DEBUG=fatal-errors` is not working for me, but `G_DEBUG=fatal-warnings` and `G_DEBUG=fatal-criticals` is, also check out [rest of options](https://developer.gnome.org/glib/stable/glib-running.html#G-DEBUG:CAPS). The line for gdb could be `gdb --args PROGRAM ARG1 ARG2` and then inside gdb issue the commands: `set env G_DEBUG=fatal-criticals` and then `run` – Nelson Mar 02 '15 at 15:21

score 20 · Accepted Answer · answered Apr 26 '11 at 08:10

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Break on g_log(). This covers all cases like g_warning(), g_critical(), etc.

answered Apr 26 '11 at 08:10

ptomato

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The useful gdb commands are: `break g_log if log_level == G_LOG_LEVEL_CRITICAL` and `break g_log if log_level == G_LOG_LEVEL_WARNING` – Mildred Jul 06 '11 at 07:08

How do I get GDB to break on a GLib assertion failure?

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