Hi y’all! Long time lurker, first time poster. I recently read @aloctavodia 's book on Bayesian Analysis with Python and enthusiastically fitted a Gamma BART model last Friday. Today when I came back to the model it won’t even make it one step into sampling and fails with “OverflowError: Python int …

Could you post the model code you ran, along with the full error traceback you got?

Unfortunately I can’t post the full model but it is a model with a BART variable that I pass into a pm.Gamma() using its mu and sigma. The point of failure happens at pm.sample() and the key points in the stack trace are: strace.record(draw.point, draw.stats) for data, vars in zip(self._stats, sam…

Can you show the full original traceback?

Yup: In sample(draws, tune, chains, cores, random_seed, progressbar, progressbar_theme, step, var_names, nuts_sampler, initvals, init, jitter_max_retries, n_init, trace, discard_tuned_samples, compute_convergence_checks, keep_warning_stat, return_inferencedata, idata_kwargs, nuts_sampler_kwargs, ca…

Yes this is very weird one. Did you see any of these already on pymc-bart @aloctavodia @gstechschulte ? How did you install PyMC and pymc-bart @krishasenbein , which package versions do you have installed, and which OS (Mac, Linux or Windows) – maybe that could be a reason @jessegrabowski @ricardoV…

Sorry for the late reply. @krishasenbein This should be fixed now. Can you try installing pymc-bart from GitHub `pip install git+https://github.com/pymc-devs/pymc-bart.git` (a new release will be available soon).

Hi @aloctavodia ! Just tried the same model that was giving me this issue before and it is running fine now, no more error. Thank you for the fix! Out of curiosity, what was the issue? :eyes:

Thanks! I am seeing issues now with plot_convergence() which is not outputting anything anymore, and compute_variable_importance(), which is now giving me an issue about “sample_stats”: `File ~/.venv/lib64/python3.11/site-packages/pymc_bart/utils.py:887, in compute_variable_importance(idata, bartrv…

`plot_convergence` was deprecated in favor of arviz_plots.plot_convergence_dist — arviz-plots dev documentation . You should get a warning message. The error is telling that your idata object does not have a `sample_stats` group, which is weird. Can you double-check?

Overflow issues with PyMC-BART

Questions version agnostic

ricardoV94 October 22, 2025, 2:51pm 9

It was discovered here: OverflowError: Python int too large to convert to C long

Topic		Replies	Views
OverflowError: Python int too large to convert to C long v5 bug	14	579	October 21, 2025
OverflowError: Results too large v5	6	229	July 28, 2024
EOF Error with PyMC BART on M2 Mac General bart	2	501	August 22, 2023
PyTensor Problem with PyMC-BART in Google Colab? General bart	4	287	September 26, 2024
[HMC] OverflowError: Python int too large to convert to C long Questions	7	4502	December 17, 2018

Overflow issues with PyMC-BART

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