Interpreting Stack Traces

When an unhandled error occurs POLARIS will generate a stack trace as shown below:

2023-06-07 10:14:57,879 Thread: 140507642888384 | [NOTICE] Turned on signal handler
2023-06-07 10:14:57,880 Thread: 140507642888384 | [NOTICE] There are 3 arguments:
2023-06-07 10:14:57,880 Thread: 140507642888384 | [NOTICE] scenario_abm.modified.json
2023-06-07 10:14:57,880 Thread: 140507642888384 | [NOTICE] 30
2023-06-07 10:14:57,881 Thread: 140507642888384 | [NOTICE] Running in Release mode
2023-06-07 10:14:57,895 Thread: 140507642888384 | [NOTICE] reading scenario data from scenario_abm.modified.json...
2023-06-07 10:14:58,335 Thread: 140507642888384 | [  WARN] unknown database schema 'Popsyn'
2023-06-07 10:14:58,714 Thread: 140507642888384 | [NOTICE] allocating data structures...
2023-06-07 10:14:58,839 Thread: 140507642888384 | [NOTICE] reading network data...
2023-06-07 11:24:55,728 Thread: 140507642873600 | [ ERROR] Error: signal 2: SIGINT
2023-06-07 11:24:55,729 Thread: 140507642873600 | [ ERROR] Stack trace:
2023-06-07 11:24:55,812 Thread: 140507642873600 | [ ERROR] 1   0x563f39dafa27 (null) + 94829553580583
2   0x563f39db0470 (null) + 94829553583216
3   0x7fca7c44d090 (null) + 140507645005968
4   0x7fca7c60b374 pthread_cond_wait + 532
5   0x7fca7c85d2d0 std::condition_variable::wait(std::unique_lock<std::mutex>&) + 16
6   0x563f3a1ae353 polaris::World::Wait_At_Finish_Gate() + 99
7   0x563f3a1b00ab polaris::Simulation_Loop(int) + 91
8   0x7fca7c8636b4 (null) + 140507649291956
9   0x7fca7c604609 (null) + 140507646805513
10  0x7fca7c529133 clone + 67

While this does not give a precise line number, in most cases it should be enough to track down the error. In the example the program was interrupted (signal 2: SIGINT), but we can still see what it was doing at the time it was interrupted.

When that isn’t enough

If the above information isn’t enough to track down the root cause - the next step would be to run the offending model through a debugger.