pysr/julia_import.py

import os
import sys
import warnings

if "juliacall" in sys.modules:
    warnings.warn(
        "juliacall module already imported. Make sure that you have set `PYTHON_JULIACALL_HANDLE_SIGNALS=yes` to avoid segfaults."
    )

# Required to avoid segfaults (https://juliapy.github.io/PythonCall.jl/dev/faq/)
if os.environ.get("PYTHON_JULIACALL_HANDLE_SIGNALS", "yes") != "yes":
    warnings.warn(
        "PYTHON_JULIACALL_HANDLE_SIGNALS environment variable is set to something other than 'yes' or ''. "
        + "You will experience segfaults if running with multithreading."
    )

if os.environ.get("JULIA_NUM_THREADS", "auto") != "auto":
    warnings.warn(
        "JULIA_NUM_THREADS environment variable is set to something other than 'auto', "
        "so PySR was not able to set it. You may wish to set it to `'auto'` for full use "
        "of your CPU."
    )

# TODO: Remove these when juliapkg lets you specify this
for k, default in (
    ("PYTHON_JULIACALL_HANDLE_SIGNALS", "yes"),
    ("JULIA_NUM_THREADS", "auto"),
    ("JULIA_OPTIMIZE", "3"),
):
    os.environ[k] = os.environ.get(k, default)

from juliacall import Main as jl  # type: ignore