gh-71052: Add test exclusions to support running the test suite on Android (#115918)

Author: mhsmith

Lib/test/support/__init__.py

@@ -532,24 +532,33 @@ def requires_debug_ranges(reason='requires co_positions / debug_ranges'):
 is_emscripten = sys.platform == "emscripten"
 is_wasi = sys.platform == "wasi"
 
-# Apple mobile platforms (iOS/tvOS/watchOS) are POSIX-like but do not
-# have subprocess or fork support.
 is_apple_mobile = sys.platform in {"ios", "tvos", "watchos"}
 is_apple = is_apple_mobile or sys.platform == "darwin"
 
 has_fork_support = hasattr(os, "fork") and not (
+    # WASM and Apple mobile platforms do not support subprocesses.
     is_emscripten
     or is_wasi
     or is_apple_mobile
+
+    # Although Android supports fork, it's unsafe to call it from Python because
+    # all Android apps are multi-threaded.
+    or is_android
 )
 
 def requires_fork():
     return unittest.skipUnless(has_fork_support, "requires working os.fork()")
 
 has_subprocess_support = not (
+    # WASM and Apple mobile platforms do not support subprocesses.
     is_emscripten
     or is_wasi
     or is_apple_mobile
+
+    # Although Android supports subproceses, they're almost never useful in
+    # practice (see PEP 738). And most of the tests that use them are calling
+    # sys.executable, which won't work when Python is embedded in an Android app.
+    or is_android
 )
 
 def requires_subprocess():

Lib/test/support/os_helper.py

@@ -198,6 +198,23 @@ def skip_unless_symlink(test):
     return test if ok else unittest.skip(msg)(test)
 
 
+_can_hardlink = None
+
+def can_hardlink():
+    global _can_hardlink
+    if _can_hardlink is None:
+        # Android blocks hard links using SELinux
+        # (https://stackoverflow.com/q/32365690).
+        _can_hardlink = hasattr(os, "link") and not support.is_android
+    return _can_hardlink
+
+
+def skip_unless_hardlink(test):
+    ok = can_hardlink()
+    msg = "requires hardlink support"
+    return test if ok else unittest.skip(msg)(test)
+
+
 _can_xattr = None
 
 

Lib/test/test_asyncio/test_subprocess.py

@@ -13,6 +13,8 @@
 from test import support
 from test.support import os_helper
 
+if not support.has_subprocess_support:
+    raise unittest.SkipTest("test module requires subprocess")
 
 if support.MS_WINDOWS:
     import msvcrt
@@ -47,7 +49,6 @@ def _start(self, *args, **kwargs):
         self._proc.pid = -1
 
 
-@support.requires_subprocess()
 class SubprocessTransportTests(test_utils.TestCase):
     def setUp(self):
         super().setUp()
@@ -111,7 +112,6 @@ def test_subprocess_repr(self):
         transport.close()
 
 
-@support.requires_subprocess()
 class SubprocessMixin:
 
     def test_stdin_stdout(self):

Lib/test/test_compileall.py

@@ -977,7 +977,7 @@ class CommandLineTestsNoSourceEpoch(CommandLineTestsBase,
 
 
 
-@unittest.skipUnless(hasattr(os, 'link'), 'requires os.link')
+@os_helper.skip_unless_hardlink
 class HardlinkDedupTestsBase:
     # Test hardlink_dupes parameter of compileall.compile_dir()
 

Lib/test/test_fcntl.py

@@ -129,7 +129,8 @@ def test_fcntl_bad_file_overflow(self):
             fcntl.fcntl(BadFile(INT_MIN - 1), fcntl.F_SETFL, os.O_NONBLOCK)
 
     @unittest.skipIf(
-        platform.machine().startswith('arm') and platform.system() == 'Linux',
+        any(platform.machine().startswith(name) for name in {"arm", "aarch"})
+        and platform.system() in {"Linux", "Android"},
         "ARM Linux returns EINVAL for F_NOTIFY DN_MULTISHOT")
     def test_fcntl_64_bit(self):
         # Issue #1309352: fcntl shouldn't fail when the third arg fits in a

Lib/test/test_interpreters/test_lifecycle.py

@@ -164,6 +164,7 @@ def test_sys_path_0(self):
 
 class FinalizationTests(TestBase):
 
+    @support.requires_subprocess()
     def test_gh_109793(self):
         # Make sure finalization finishes and the correct error code
         # is reported, even when subinterpreters get cleaned up at the end.

Lib/test/test_os.py

@@ -1592,6 +1592,9 @@ def test_yields_correct_dir_fd(self):
     @unittest.skipIf(
         support.is_emscripten, "Cannot dup stdout on Emscripten"
     )
+    @unittest.skipIf(
+        support.is_android, "dup return value is unpredictable on Android"
+    )
     def test_fd_leak(self):
         # Since we're opening a lot of FDs, we must be careful to avoid leaks:
         # we both check that calling fwalk() a large number of times doesn't
@@ -2492,8 +2495,10 @@ def test_listdir(self):
         # test listdir without arguments
         current_directory = os.getcwd()
         try:
-            os.chdir(os.sep)
-            self.assertEqual(set(os.listdir()), set(os.listdir(os.sep)))
+            # The root directory is not readable on Android, so use a directory
+            # we created ourselves.
+            os.chdir(self.dir)
+            self.assertEqual(set(os.listdir()), expected)
         finally:
             os.chdir(current_directory)
 
@@ -4838,7 +4843,7 @@ def check_entry(self, entry, name, is_dir, is_file, is_symlink):
                                os.name == 'nt')
 
     def test_attributes(self):
-        link = hasattr(os, 'link')
+        link = os_helper.can_hardlink()
         symlink = os_helper.can_symlink()
 
         dirname = os.path.join(self.path, "dir")

Lib/test/test_pathlib/test_pathlib.py

@@ -796,7 +796,7 @@ def test_rmdir(self):
         self.assertFileNotFound(p.stat)
         self.assertFileNotFound(p.unlink)
 
-    @unittest.skipUnless(hasattr(os, "link"), "os.link() is not present")
+    @os_helper.skip_unless_hardlink
     def test_hardlink_to(self):
         P = self.cls(self.base)
         target = P / 'fileA'

Lib/test/test_posix.py

@@ -1270,9 +1270,10 @@ def test_get_and_set_scheduler_and_param(self):
         self.assertIn(mine, possible_schedulers)
         try:
             parent = posix.sched_getscheduler(os.getppid())
-        except OSError as e:
-            if e.errno != errno.EPERM:
-                raise
+        except PermissionError:
+            # POSIX specifies EPERM, but Android returns EACCES. Both errno
+            # values are mapped to PermissionError.
+            pass
         else:
             self.assertIn(parent, possible_schedulers)
         self.assertRaises(OSError, posix.sched_getscheduler, -1)
@@ -1287,9 +1288,8 @@ def test_get_and_set_scheduler_and_param(self):
             try:
                 posix.sched_setscheduler(0, mine, param)
                 posix.sched_setparam(0, param)
-            except OSError as e:
-                if e.errno != errno.EPERM:
-                    raise
+            except PermissionError:
+                pass
             self.assertRaises(OSError, posix.sched_setparam, -1, param)
 
         self.assertRaises(OSError, posix.sched_setscheduler, -1, mine, param)

Lib/test/test_pty.py

@@ -1,17 +1,15 @@
-import sys
 import unittest
 from test.support import (
-    is_apple_mobile, is_emscripten, is_wasi, reap_children, verbose
+    is_android, is_apple_mobile, is_emscripten, is_wasi, reap_children, verbose
 )
 from test.support.import_helper import import_module
 from test.support.os_helper import TESTFN, unlink
 
 # Skip these tests if termios is not available
 import_module('termios')
 
-# Skip tests on WASM platforms, plus iOS/tvOS/watchOS
-if is_apple_mobile or is_emscripten or is_wasi:
-    raise unittest.SkipTest(f"pty tests not required on {sys.platform}")
+if is_android or is_apple_mobile or is_emscripten or is_wasi:
+    raise unittest.SkipTest("pty is not available on this platform")
 
 import errno
 import os

Lib/test/test_venv.py

@@ -19,8 +19,9 @@
 import tempfile
 from test.support import (captured_stdout, captured_stderr,
                           skip_if_broken_multiprocessing_synchronize, verbose,
-                          requires_subprocess, is_apple_mobile, is_emscripten,
-                          is_wasi, requires_venv_with_pip, TEST_HOME_DIR,
+                          requires_subprocess, is_android, is_apple_mobile,
+                          is_emscripten, is_wasi,
+                          requires_venv_with_pip, TEST_HOME_DIR,
                           requires_resource, copy_python_src_ignore)
 from test.support.os_helper import (can_symlink, EnvironmentVarGuard, rmtree)
 import unittest
@@ -39,10 +40,8 @@
     or sys._base_executable != sys.executable,
     'cannot run venv.create from within a venv on this platform')
 
-# Skip tests on WASM platforms, plus iOS/tvOS/watchOS
-if is_apple_mobile or is_emscripten or is_wasi:
-    raise unittest.SkipTest(f"venv tests not required on {sys.platform}")
-
+if is_android or is_apple_mobile or is_emscripten or is_wasi:
+    raise unittest.SkipTest("venv is not available on this platform")
 
 @requires_subprocess()
 def check_output(cmd, encoding=None):

Misc/NEWS.d/next/Tests/2024-02-25-16-28-26.gh-issue-71052.lSb9EC.rst

@@ -0,0 +1 @@
+Add test exclusions to support running the test suite on Android.