Troubleshooting

Known Issues

Problems installing CARS on system with proj and gdal

Rasterio and Fiona must be compiled with your version of proj and gdal. Pip install these packages in no-binary mode.

My job is killed using Multiprocessing

It can happen for several reasons:

• Out of memory: check the profiling graphs to see if CARS consumes the memory you were expecting.

• SegFault in worker: If a segmentation fault happens in a worker, in a binded c++ code, no error message is displayed.

Dask workers die

Dask workers can die for several reasons: * Out of memory in worker * unmanaged memory can increase and kill the worker

Debugging Tips

A lot of information in contained in the logs outdir/logs/*log files. Moreover, a profiling report is generated, and can explain the majority of crashes.

For quality issues, you should visualize intermediate results, that can be saved by activating the save_intermediate_data option in the configuration file of each application.

When the crashes occur in a worker, it can be tricky to debug. You can try the following tips: * Change the cluster type to squential to have logs in the main process. Be careful, this can be very slow : use it on small datasets only. * Use the roi option to reduce the data size.