Allow some numba exceptions on 32 bit systems, warn on non-x86

Specifying the exception type allows only explicit errors,
not silently wrong answers

Numba has been observed to give wrong answers on mipsel
and crash on ppc64el.

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Forwarded: no

Gbp-Pq: Name numba_fail_32bit.patch

diff --git a/pandas/core/window/numba_.py b/pandas/core/window/numba_.py
index d6f28c9005b9ed7f77727dbbf7c6169747f4e56b..eab974a98f6f17a1f67de4e4dcf11a3f1505a2fe 100644 (file)
--- a/pandas/core/window/numba_.py
+++ b/pandas/core/window/numba_.py
@@ -6,7 +6,10 @@ import numpy as np
 
 from pandas._typing import Scalar
 from pandas.compat._optional import import_optional_dependency
-
+import platform
+import re
+import warnings
+warn_numba_platform = "Non-x86 system detected, Numba may give wrong results or crash" if not bool(re.match('i.?86|x86',platform.uname()[4])) else False
 
 def make_rolling_apply(
     func: Callable[..., Scalar],
@@ -37,6 +40,8 @@ def make_rolling_apply(
     Numba function
     """
     numba = import_optional_dependency("numba")
+    if warn_numba_platform:
+        warnings.warn(warn_numba_platform)
 
     if parallel:
         loop_range = numba.prange

diff --git a/pandas/tests/window/test_numba.py b/pandas/tests/window/test_numba.py
index cc8aef1779b46132605df9af41bc679b0c837981..1b006d1110b8e5835c4a46a8a07aa7b14f1513e7 100644 (file)
--- a/pandas/tests/window/test_numba.py
+++ b/pandas/tests/window/test_numba.py
@@ -5,9 +5,15 @@ import pandas.util._test_decorators as td
 
 from pandas import Series
 import pandas._testing as tm
+from pandas.compat import is_platform_32bit
+try:
+    from numba.core.errors import UnsupportedParforsError
+except ImportError:
+    UnsupportedParforsError = ImportError
 
 
 @td.skip_if_no("numba", "0.46.0")
+@pytest.mark.xfail(condition=is_platform_32bit(), raises=UnsupportedParforsError, reason="some Numba functionality is not available on 32 bit systems", strict=False)
 @pytest.mark.filterwarnings("ignore:\\nThe keyword argument")
 # Filter warnings when parallel=True and the function can't be parallelized by Numba
 class TestApply: