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I try to use Cython with Python3 (Anaconda3) under Windows 7. After having solved a bug in distutils by editing the file cygwinccompiler.py (cf. Building minimal cython file with python 3.3 (Anaconda) under windows 7), modules can be built without any problems:

C:\path\testcython> python setup.py build 
running build
running build_ext
cythoning testcython.pyx to testcython.c
building 'testcython' extension
C:\Prog\Anaconda3\Scripts\gcc.bat -mdll -O -Wall -IC:\Prog\Anaconda3\include -IC
:\Prog\Anaconda3\include -c testcython.c -o build\temp.win-amd64-3.4\Release\tes
tcython.o
writing build\temp.win-amd64-3.4\Release\testcython.def
C:\Prog\Anaconda3\Scripts\gcc.bat -shared -s build\temp.win-amd64-3.4\Release\te
stcython.o build\temp.win-amd64-3.4\Release\testcython.def -LC:\Prog\Anaconda3\l
ibs -LC:\Prog\Anaconda3\PCbuild\amd64 -lpython34 -lmsvcr100 -o build\lib.win-amd
64-3.4\testcython.pyd

However, as soon as there is an import or a print statement in the .pyx file, the produced .pyd file makes Python crash. For example, if testcython.pyx contains

def say_hello_to(name):
    print('Hello '+name)

it gives

In [1]: import testcython # no crash here

In [2]: testcython.say_hello_to('Tom')
Hello Tom

Here the "Python.exe has stopped working" window pops up and it's finished.

In that kind of situation (crash without error log, segmentation fault I suppose), what can I do to understand the problem?

Does anyone understand what happens here with Cython, Python 3 (Anaconda3) under Windows?

PS: no problem with Python 2.7 (Anaconda).

Edit: traceback produced by the module faulthandler

If testcython.pyx just contains:

print('Test print... Will it crash?')

or

import mod # where mod.py is a nearly empty module in the working directory

or

import sys

python crashes and I get:

$ python -X faulthandler -c 'import testcython'
Test print... Will it crash?
Fatal Python error: Segmentation fault

Current thread 0x000013e0 (most recent call first):
  File "<frozen importlib._bootstrap>", line 321 in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1715 in load_module
  File "<frozen importlib._bootstrap>", line 539 in _check_name_wrapper
  File "<frozen importlib._bootstrap>", line 1161 in _load_backward_compatible
  File "<frozen importlib._bootstrap>", line 1191 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 2226 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 2237 in _find_and_load
  File "<string>", line 1 in <module>
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paugier
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1 Answers1

3

It seems like the build is failing to link to the appropriate libraries and the print (write to terminal) is causing seg-faults.

let's go back to the build process. can you use pip instead of setup.py build?

Can you work under Linux :)

Jonathan
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  • Actually I usually work under Linux... Unfortunately, there are situations when you have to work under close OS, like Mac or Windows. I was in such situation when I asked this question. Finally, I just had to come back to Python 2.7 (with Anaconda) for which there is no problem. – paugier Apr 01 '15 at 08:23