# 5.5. My application crashes. What can I do?¶

## 5.5.1. Does it crash at the beginning or at the end?¶

Check if Nanos++ was built with the allocator disabled.

## 5.5.2. Get a backtrace¶

The first step would be to obtain a backtrace using gdb. (see GNU GDB website).

### 5.5.2.1. Ways to run gdb¶

A typical approach could be:

$gdb --args program parameters  If your applications needs some NX_ARGS you can pass them like this: $ NX_ARGS="..." gdb --args program parameters


or set in the environment using export or setenv as usual before running gdb.

If you are running in a batch queue (not interactively) you will have to use gdb in batch mode. Pass the flags --batch and -ex like this:



## 5.5.3. I cannot get a backtrace¶

If there is no backtrace, this can be a symptom of a low stack size. You can increase it with NX_STACK_SIZE (see Running OmpSs Programs).

If this does not solve your problem, we suggest to follow these steps:
• Activate the tasks again, but follow them by a #pragma omp taskwait
• Remove the unneeded taskwait one by one.