Cython C++ tutorial: Symbol not found

Question

I am trying the Cython tutorial which uses a C++ vector (https://cython.readthedocs.io/en/latest/src/tutorial/cython_tutorial.html). It compiles fine, but when I import the module I receive Symbol not found: __ZTINSt8ios_base7failureB5cxx11E

# distutils: language=c++

from libcpp.vector cimport vector

def primes(unsigned int nb_primes):
    cdef int n, i
    cdef vector[int] p
    p.reserve(nb_primes)  # allocate memory for 'nb_primes' elements.

    n = 2
    while p.size() < nb_primes:  # size() for vectors is similar to len()
        for i in p:
            if n % i == 0:
                break
        else:
            p.push_back(n)  # push_back is similar to append()
        n += 1

    # Vectors are automatically converted to Python
    # lists when converted to Python objects.
    return p

My setup.py:

from setuptools import setup, Extension
from Cython.Build import cythonize
import os

os.environ["CC"] = "gcc-10"
os.environ["CXX"] = "gcc-10"

ext_modules = [
    Extension(
        "test",
        ["test.pyx"],
        language = "c++"
    )
]

setup(
    ext_modules = cythonize(ext_modules, annotate=True),
)

What have I done wrong?

Edit: By removing the os.environ settings and setting language level to 3 (instead of the default, 2 ?!!) I was able to fix this. Thanks to everyone who helped.

Cython C++ tutorial: Symbol not found

0 Answers