Description: HDF5 and Stata I/O are broken on some architectures

Fix some issues, warn on use and xfail tests for the remainder

Everything that has a run=False xfail in here should also be in
the run-and-ignore set in debian/tests/numbatests

armhf TestHDF5Store::test*encoding only sometimes crashes
(1.1.3+dfsg-1 passed on build but failed autopkgtest)

HDF5 and Stata are known to fail on big-endian architectures
Stata was previously seen to fail on qemu-ppc64el, but not real ppc64el

Author: Andreas Tille <tille@debian.org>, Graham Inggs <ginggs@debian.org>, Yaroslav Halchenko <debian@onerussian.com>, Rebecca N. Palmer <rebecca_palmer@zoho.com>
Bug-Debian: https://bugs.debian.org/877419
Bug: partly https://github.com/pandas-dev/pandas/issues/54396
Forwarded: no

--- a/pyproject.toml
+++ b/pyproject.toml
@@ -495,6 +495,7 @@ filterwarnings = [
   "error:::pandas",
   "error::ResourceWarning",
   "error::pytest.PytestUnraisableExceptionWarning",
+  "ignore:Non-x86 system detected:UserWarning:pandas",
   # TODO(PY311-minimum): Specify EncodingWarning
   # Ignore 3rd party EncodingWarning but raise on pandas'
   "ignore:.*encoding.* argument not specified",
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -24,6 +24,10 @@ from typing import (
     overload,
 )
 import warnings
+import platform
+import sys
+from pandas.compat import is_platform_little_endian
+warn_hdf_platform = "Non-x86 system detected, HDF(5) format I/O may give wrong results (particularly on files created with older versions) or crash - https://bugs.debian.org/877419" if (((platform.uname()[4].startswith('arm') or platform.uname()[4].startswith('aarch')) and sys.maxsize<2**33) or not is_platform_little_endian()) else False
 
 import numpy as np
 
@@ -560,6 +564,8 @@ class HDFStore:
         fletcher32: bool = False,
         **kwargs,
     ) -> None:
+        if warn_hdf_platform:
+            warnings.warn(warn_hdf_platform)
         if "format" in kwargs:
             raise ValueError("format is not a defined argument for HDFStore")
 
@@ -781,7 +787,10 @@ class HDFStore:
             self._handle.flush()
             if fsync:
                 with suppress(OSError):
-                    os.fsync(self._handle.fileno())
+                    if is_platform_little_endian():
+                        os.fsync(self._handle.fileno())
+                    else:
+                        os.sync() # due to a pytables bad-cast bug, fileno is invalid on 64-bit big-endian#
 
     def get(self, key: str):
         """
--- a/pandas/io/stata.py
+++ b/pandas/io/stata.py
@@ -29,6 +29,8 @@ from typing import (
     cast,
 )
 import warnings
+from pandas.compat import is_platform_little_endian
+warn_stata_platform = "Non-x86 system detected, Stata format I/O may give wrong results (particularly on strings) - https://bugs.debian.org/877419" if not is_platform_little_endian() else False
 
 import numpy as np
 
@@ -971,6 +973,8 @@ class StataParser:
         # NOTE: the byte type seems to be reserved for categorical variables
         # with a label, but the underlying variable is -127 to 100
         # we're going to drop the label and cast to int
+        if warn_stata_platform:
+            warnings.warn(warn_stata_platform)
         self.DTYPE_MAP = dict(
             [(i, np.dtype(f"S{i}")) for i in range(1, 245)]
             + [
--- a/pandas/tests/io/pytables/test_file_handling.py
+++ b/pandas/tests/io/pytables/test_file_handling.py
@@ -28,6 +28,10 @@ from pandas.tests.io.pytables.common imp
     ensure_clean_store,
     tables,
 )
+import platform
+import re
+import sys
+is_crashing_arch=bool((platform.uname()[4].startswith('arm') or platform.uname()[4].startswith('aarch')) and sys.maxsize<2**33) # meant for armhf, though this form will also skip on armel - uname = kernel arch
 
 from pandas.io import pytables
 from pandas.io.pytables import Term
@@ -297,6 +301,7 @@ def test_complibs(tmp_path, lvl, lib, re
                 assert node.filters.complib == lib
 
 
+@pytest.mark.xfail(condition=is_crashing_arch,reason="https://bugs.debian.org/790925",strict=False,run=False)
 @pytest.mark.skipif(
     not is_platform_little_endian(), reason="reason platform is not little endian"
 )
@@ -329,6 +334,7 @@ def test_encoding(setup_path):
     ],
 )
 @pytest.mark.parametrize("dtype", ["category", object])
+@pytest.mark.xfail(condition=is_crashing_arch,reason="https://bugs.debian.org/790925",strict=False,run=False)
 def test_latin_encoding(tmp_path, setup_path, dtype, val):
     enc = "latin-1"
     nan_rep = ""
--- a/pandas/tests/io/pytables/test_append.py
+++ b/pandas/tests/io/pytables/test_append.py
@@ -22,6 +22,10 @@ from pandas.tests.io.pytables.common imp
     _maybe_remove,
     ensure_clean_store,
 )
+import platform
+import re
+import sys
+is_crashing_arch=bool((platform.uname()[4].startswith('arm') or platform.uname()[4].startswith('aarch')) and sys.maxsize<2**33) # meant for armhf, though this form will also skip on armel - uname = kernel arch
 
 pytestmark = pytest.mark.single_cpu
 
@@ -282,6 +286,7 @@ def test_append_all_nans(setup_path):
             tm.assert_frame_equal(store["df2"], df, check_index_type=True)
 
 
+@pytest.mark.xfail(condition=is_crashing_arch,reason="https://bugs.debian.org/790925",strict=False,run=False)
 def test_append_frame_column_oriented(setup_path):
     with ensure_clean_store(setup_path) as store:
         # column oriented
--- a/pandas/tests/io/pytables/test_store.py
+++ b/pandas/tests/io/pytables/test_store.py
@@ -30,6 +30,10 @@ from pandas.io.pytables import (
     HDFStore,
     read_hdf,
 )
+import platform
+import re
+import sys
+is_crashing_arch=bool((platform.uname()[4].startswith('arm') or platform.uname()[4].startswith('aarch')) and sys.maxsize<2**33) # meant for armhf, though this form will also skip on armel - uname = kernel arch
 
 pytestmark = pytest.mark.single_cpu
 
@@ -880,6 +884,7 @@ def test_start_stop_fixed(setup_path):
         df.iloc[8:10, -2] = np.nan
 
 
+@pytest.mark.xfail(condition=is_crashing_arch,reason="https://bugs.debian.org/790925",strict=False,run=False)
 def test_select_filter_corner(setup_path):
     df = DataFrame(np.random.default_rng(2).standard_normal((50, 100)))
     df.index = [f"{c:3d}" for c in df.index]
--- a/pandas/tests/io/pytables/test_read.py
+++ b/pandas/tests/io/pytables/test_read.py
@@ -6,7 +6,7 @@ import numpy as np
 import pytest
 
 from pandas._libs.tslibs import Timestamp
-from pandas.compat import is_platform_windows
+from pandas.compat import is_platform_windows, is_platform_little_endian
 
 import pandas as pd
 from pandas import (
@@ -172,6 +172,7 @@ def test_pytables_native2_read(datapath)
     assert isinstance(d1, DataFrame)
 
 
+@pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of hdf on non-little endian",strict=False,raises=AttributeError)
 def test_legacy_table_fixed_format_read_py2(datapath):
     # GH 24510
     # legacy table with fixed format written in Python 2
@@ -187,6 +188,7 @@ def test_legacy_table_fixed_format_read_
     tm.assert_frame_equal(expected, result)
 
 
+@pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of hdf on non-little endian",strict=False,raises=AttributeError)
 def test_legacy_table_fixed_format_read_datetime_py2(datapath):
     # GH 31750
     # legacy table with fixed format and datetime64 column written in Python 2
@@ -370,6 +372,7 @@ def test_read_hdf_series_mode_r(tmp_path
 
 @pytest.mark.filterwarnings(r"ignore:Period with BDay freq is deprecated:FutureWarning")
 @pytest.mark.filterwarnings(r"ignore:PeriodDtype\[B\] is deprecated:FutureWarning")
+@pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of hdf on non-little endian",strict=False,raises=AttributeError)
 def test_read_py2_hdf_file_in_py3(datapath):
     # GH 16781
 
--- a/pandas/tests/io/test_stata.py
+++ b/pandas/tests/io/test_stata.py
@@ -34,6 +34,8 @@ from pandas.io.stata import (
     read_stata,
 )
 
+from pandas.compat import is_platform_little_endian
+pytestmark = pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of test_stata on non-little endian",strict=False)
 
 @pytest.fixture
 def mixed_frame():
--- a/pandas/tests/io/pytables/test_timezones.py
+++ b/pandas/tests/io/pytables/test_timezones.py
@@ -8,6 +8,7 @@ import pytest
 
 from pandas._libs.tslibs.timezones import maybe_get_tz
 import pandas.util._test_decorators as td
+from pandas.compat import is_platform_little_endian
 
 import pandas as pd
 from pandas import (
@@ -312,6 +313,7 @@ def test_store_timezone(setup_path):
         tm.assert_frame_equal(result, df)
 
 
+@pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of hdf on non-little endian",strict=False,raises=AttributeError)
 def test_legacy_datetimetz_object(datapath):
     # legacy from < 0.17.0
     # 8260
@@ -364,6 +366,7 @@ def test_read_with_where_tz_aware_index(
     tm.assert_frame_equal(result, expected)
 
 
+@pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of hdf on non-little endian",strict=False,raises=AttributeError)
 def test_py2_created_with_datetimez(datapath):
     # The test HDF5 file was created in Python 2, but could not be read in
     # Python 3.
--- a/pandas/tests/io/test_common.py
+++ b/pandas/tests/io/test_common.py
@@ -18,7 +18,7 @@ import tempfile
 import numpy as np
 import pytest
 
-from pandas.compat import is_platform_windows
+from pandas.compat import is_platform_windows, is_platform_little_endian
 import pandas.util._test_decorators as td
 
 import pandas as pd
@@ -305,11 +305,11 @@ Look,a snake,🐍"""
                 "pyarrow",
                 ("io", "data", "feather", "feather-0_3_1.feather"),
             ),
-            (
+            pytest.param(
                 pd.read_hdf,
                 "tables",
                 ("io", "data", "legacy_hdf", "datetimetz_object.h5"),
-            ),
+            marks=pytest.mark.xfail(condition=not is_platform_little_endian(),reason="known failure of hdf on non-little endian",strict=False,raises=AttributeError)),
             (pd.read_stata, "os", ("io", "data", "stata", "stata10_115.dta")),
             (pd.read_sas, "os", ("io", "sas", "data", "test1.sas7bdat")),
             (pd.read_json, "os", ("io", "json", "data", "tsframe_v012.json")),
--- a/pandas/_testing/_warnings.py
+++ b/pandas/_testing/_warnings.py
@@ -13,6 +13,7 @@ from typing import (
     cast,
 )
 import warnings
+import platform
 
 from pandas.compat import PY311
 
@@ -187,6 +188,8 @@ def _assert_caught_no_extra_warnings(
                 # pyproject.toml errors on EncodingWarnings in pandas
                 # Ignore EncodingWarnings from other libraries
                 continue
+            if (actual_warning.category==UserWarning and "Non-x86 system detected" in str(actual_warning.message) and not bool(re.match('i.?86|x86',platform.uname()[4]))) or (actual_warning.category==RuntimeWarning and "invalid value encountered" in str(actual_warning.message) and 'mips' in platform.uname()[4]):
+                continue
             extra_warnings.append(
                 (
                     actual_warning.category.__name__,