Troubleshooting and Common Errors

`python: command not found`

The Makefiles default to PYTHON ?= python. Build with:

make clean
make PYTHON=python3 all

`No module named Cython` or `numpy`

Install the wrapper build dependencies:

python3 -m pip install --user numpy Cython

`No module named cyballs`

Confirm the extension was built for the Python interpreter being used:

make clean
make PYTHON=python3 all
python3 -c "from cyballs import cballs; print(cballs)"

Older notes may mention cballys; the current source module is cyballs.

OpenMP Link or Runtime Errors

The default GNU build uses -fopenmp and links -lgomp. Verify that CC and OMPFLAG in Makefile_machine match the installed compiler. If OpenMP is unavailable, set OPENMPMACHINE = 0, rebuild cleanly, and omit numberThreads expectations from benchmarks.

GSL or CFITSIO Headers/Libraries Not Found

The repository defaults use bundled GSL and CFITSIO paths. If switching to system libraries, set GSLINTERNAL = 0 or CFITSIOLIBON = 0 and update the include/library paths in Makefile_machine. Always run make clean after changing these switches.

Parameter Was Not Read

Command-line tokens must use name=value with no spaces. Parameter files should use full parameter names. Check the compiled ./cballs --help because enabled add-ons determine which names are available.

Empty or Unexpected Histograms

Check:

input format and column order;
catalog units versus rminHist and rangeN;
iCatalogs selection;
search method compatibility with the geometry;
requested options and compile-time TWOPCFON/TPCFON settings;
the generated used-values file.

Segmentation Fault in a Python Loop

Copy NumPy results before cleanup and call clean_all once per completed run. If repeated in-process runs remain unstable, isolate calculations in separate processes and report the minimal parameter set, platform, compiler, and commit hash to the issue tracker.