Revert "GH-128469: warn when libpython was loaded from outside the build directory (#128645)"

This reverts commit 29b3ce8.

Author: encukou

Lib/test/test_getpath.py

@@ -1,13 +1,7 @@
 import copy
 import ntpath
-import os
 import pathlib
 import posixpath
-import shutil
-import subprocess
-import sys
-import sysconfig
-import tempfile
 import unittest
 
 from test.support import verbose
@@ -870,37 +864,6 @@ def test_PYTHONHOME_in_venv(self):
         actual = getpath(ns, expected)
         self.assertEqual(expected, actual)
 
-
-class RealGetPathTests(unittest.TestCase):
-    @unittest.skipUnless(
-        sysconfig.is_python_build(),
-        'Test only available when running from the buildir',
-    )
-    @unittest.skipUnless(
-        any(sys.platform.startswith(p) for p in ('linux', 'freebsd', 'centos')),
-        'Test only support on Linux-like OS-es (support LD_LIBRARY_PATH)',
-    )
-    @unittest.skipUnless(
-        sysconfig.get_config_var('LDLIBRARY') != sysconfig.get_config_var('LIBRARY'),
-        'Test only available when using a dynamic libpython',
-    )
-    def test_builddir_wrong_library_warning(self):
-        library_name = sysconfig.get_config_var('INSTSONAME')
-        with tempfile.TemporaryDirectory() as tmpdir:
-            shutil.copy2(
-                os.path.join(sysconfig.get_config_var('srcdir'), library_name),
-                os.path.join(tmpdir, library_name)
-            )
-            env = os.environ.copy()
-            env['LD_LIBRARY_PATH'] = tmpdir
-            process = subprocess.run(
-                [sys.executable, '-c', ''],
-                env=env, check=True, capture_output=True, text=True,
-            )
-        error_msg = 'The runtime library has been loaded from outside the build directory'
-        self.assertTrue(process.stderr.startswith(error_msg), process.stderr)
-
-
 # ******************************************************************************
 
 DEFAULT_NAMESPACE = dict(

Modules/getpath.py

@@ -785,19 +785,6 @@ def search_up(prefix, *landmarks, test=isfile):
     base_exec_prefix = config.get('base_exec_prefix') or EXEC_PREFIX or base_prefix
 
 
-# ******************************************************************************
-# MISC. RUNTIME WARNINGS
-# ******************************************************************************
-
-# When running Python from the build directory, if libpython is dynamically
-# linked, the wrong library might be loaded.
-if build_prefix and library and not dirname(abspath(library)).startswith(build_prefix):
-    msg = f'The runtime library has been loaded from outside the build directory ({library})!'
-    if os_name == 'posix':
-        msg += ' Consider setting LD_LIBRARY_PATH=. to force it to be loaded from the build directory.'
-    warn(msg)
-
-
 # ******************************************************************************
 # SET pythonpath FROM _PTH FILE
 # ******************************************************************************