[BUG] double_abs test failures

[Apteryks]

Describe the bug

Running the test suite of Cython 3.0.11 with GNU Guix, I see the following doctests failures:

======================================================================
FAIL: double_abs (complex_numbers_cpp)
Doctest: complex_numbers_cpp.double_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/gnu/store/lp8ch4rn10whzyajnzv216d2a2v163c7-python-3.10.7/lib/python3.10/doctest.py", line 2221, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for complex_numbers_cpp.double_abs
  File "/tmp/guix-build-python-cython-3.0.11.drv-0/cython-3.0.11/TEST_TMP/14/run/cpp/complex_numbers_cpp/complex_numbers_cpp.cpython-310-x86_64-linux-gnu.so", line unknown line number, in double_abs

----------------------------------------------------------------------
File "/tmp/guix-build-python-cython-3.0.11.drv-0/cython-3.0.11/TEST_TMP/14/run/cpp/complex_numbers_cpp/complex_numbers_cpp.cpython-310-x86_64-linux-gnu.so", line ?, in complex_numbers_cpp.double_abs
Failed example:
    double_abs(2 + 5j) == math.sqrt(29)
Expected:
    True
Got:
    False


======================================================================
FAIL: double_abs (complex_numbers_cpp)
Doctest: complex_numbers_cpp.double_abs
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/gnu/store/lp8ch4rn10whzyajnzv216d2a2v163c7-python-3.10.7/lib/python3.10/doctest.py", line 2221, in runTest
    raise self.failureException(self.format_failure(new.getvalue()))
AssertionError: Failed doctest test for complex_numbers_cpp.double_abs
  File "/tmp/guix-build-python-cython-3.0.11.drv-0/cython-3.0.11/TEST_TMP/14/run/cpp/complex_numbers_cpp_directives_cpp_locals_True/complex_numbers_cpp.cpython-310-x86_64-linux-gnu.so", line unknown line number, in double_abs

----------------------------------------------------------------------
File "/tmp/guix-build-python-cython-3.0.11.drv-0/cython-3.0.11/TEST_TMP/14/run/cpp/complex_numbers_cpp_directives_cpp_locals_True/complex_numbers_cpp.cpython-310-x86_64-linux-gnu.so", line ?, in complex_numbers_cpp.double_abs
Failed example:
    double_abs(2 + 5j) == math.sqrt(29)
Expected:
    True
Got:
    False


----------------------------------------------------------------------
Ran 579 tests in 86.348s

FAILED (failures=2)

The only direct dependencies added to the build environment are:
[email protected] [email protected]. GCC is at version 11.4.0.

Code to reproduce the behaviour:

Just building it with a similar environment should trigger it.

Expected behaviour

All tests should pass.

OS

GNU+Linux

Python version

3.10.7

Cython version

3.0.11

Additional context

Initially misfiled here: python/cpython#127437.

[da-woods]

Thanks for the report.

This probably just needs to be rewritten to check for a small difference rather than an exact equals. So I suspect this test failure isn't anything to really worry about. But we should fix it.