Issue #15364: Fix sysconfig.get_config_var('srcdir') to be an absolute path.

Lib/distutils/sysconfig.py

@@ -533,6 +533,23 @@ def get_config_vars(*args):
         _config_vars['prefix'] = PREFIX
         _config_vars['exec_prefix'] = EXEC_PREFIX
 
+        # Always convert srcdir to an absolute path
+        srcdir = _config_vars.get('srcdir', project_base)
+        if os.name == 'posix':
+            if python_build:
+                # If srcdir is a relative path (typically '.' or '..')
+                # then it should be interpreted relative to the directory
+                # containing Makefile.
+                base = os.path.dirname(get_makefile_filename())
+                srcdir = os.path.join(base, srcdir)
+            else:
+                # srcdir is not meaningful since the installation is
+                # spread about the filesystem.  We choose the
+                # directory containing the Makefile since we know it
+                # exists.
+                srcdir = os.path.dirname(get_makefile_filename())
+        _config_vars['srcdir'] = os.path.abspath(os.path.normpath(srcdir))
+
         # Convert srcdir into an absolute path if it appears necessary.
         # Normally it is relative to the build directory.  However, during
         # testing, for example, we might be running a non-installed python

Lib/distutils/tests/test_sysconfig.py

@@ -53,6 +53,34 @@ class SysconfigTestCase(support.EnvironGuard,
         self.assertTrue(isinstance(cvars, dict))
         self.assertTrue(cvars)
 
+    def test_srcdir(self):
+        # See Issues #15322, #15364.
+        srcdir = sysconfig.get_config_var('srcdir')
+
+        self.assertTrue(os.path.isabs(srcdir), srcdir)
+        self.assertTrue(os.path.isdir(srcdir), srcdir)
+
+        if sysconfig.python_build:
+            # The python executable has not been installed so srcdir
+            # should be a full source checkout.
+            Python_h = os.path.join(srcdir, 'Include', 'Python.h')
+            self.assertTrue(os.path.exists(Python_h), Python_h)
+            self.assertTrue(sysconfig._is_python_source_dir(srcdir))
+        elif os.name == 'posix':
+            self.assertEqual(sysconfig.get_makefile_filename(), srcdir)
+
+    def test_srcdir_independent_of_cwd(self):
+        # srcdir should be independent of the current working directory
+        # See Issues #15322, #15364.
+        srcdir = sysconfig.get_config_var('srcdir')
+        cwd = os.getcwd()
+        try:
+            os.chdir('..')
+            srcdir2 = sysconfig.get_config_var('srcdir')
+        finally:
+            os.chdir(cwd)
+        self.assertEqual(srcdir, srcdir2)
+
     def test_customize_compiler(self):
 
         # not testing if default compiler is not unix

Lib/sysconfig.py

@@ -533,28 +533,22 @@ def get_config_vars(*args):
         # the init-function.
         _CONFIG_VARS['userbase'] = _getuserbase()
 
-        if 'srcdir' not in _CONFIG_VARS:
-            _CONFIG_VARS['srcdir'] = _PROJECT_BASE
-        else:
-            _CONFIG_VARS['srcdir'] = _safe_realpath(_CONFIG_VARS['srcdir'])
-
-        # Convert srcdir into an absolute path if it appears necessary.
-        # Normally it is relative to the build directory.  However, during
-        # testing, for example, we might be running a non-installed python
-        # from a different directory.
-        if _PYTHON_BUILD and os.name == "posix":
-            base = _PROJECT_BASE
-            try:
-                cwd = os.getcwd()
-            except OSError:
-                cwd = None
-            if (not os.path.isabs(_CONFIG_VARS['srcdir']) and
-                base != cwd):
-                # srcdir is relative and we are not in the same directory
-                # as the executable. Assume executable is in the build
-                # directory and make srcdir absolute.
-                srcdir = os.path.join(base, _CONFIG_VARS['srcdir'])
-                _CONFIG_VARS['srcdir'] = os.path.normpath(srcdir)
+        # Always convert srcdir to an absolute path
+        srcdir = _CONFIG_VARS.get('srcdir', _PROJECT_BASE)
+        if os.name == 'posix':
+            if _PYTHON_BUILD:
+                # If srcdir is a relative path (typically '.' or '..')
+                # then it should be interpreted relative to the directory
+                # containing Makefile.
+                base = os.path.dirname(get_makefile_filename())
+                srcdir = os.path.join(base, srcdir)
+            else:
+                # srcdir is not meaningful since the installation is
+                # spread about the filesystem.  We choose the
+                # directory containing the Makefile since we know it
+                # exists.
+                srcdir = os.path.dirname(get_makefile_filename())
+        _CONFIG_VARS['srcdir'] = _safe_realpath(srcdir)
 
         # OS X platforms require special customization to handle
         # multi-architecture, multi-os-version installers

Lib/test/test_sysconfig.py

@@ -340,6 +340,34 @@ class TestSysConfig(unittest.TestCase):
             self.assertEqual(status, 0)
             self.assertEqual(my_platform, test_platform)
 
+    def test_srcdir(self):
+        # See Issues #15322, #15364.
+        srcdir = sysconfig.get_config_var('srcdir')
+
+        self.assertTrue(os.path.isabs(srcdir), srcdir)
+        self.assertTrue(os.path.isdir(srcdir), srcdir)
+
+        if sysconfig._PYTHON_BUILD:
+            # The python executable has not been installed so srcdir
+            # should be a full source checkout.
+            Python_h = os.path.join(srcdir, 'Include', 'Python.h')
+            self.assertTrue(os.path.exists(Python_h), Python_h)
+            self.assertTrue(sysconfig._is_python_source_dir(srcdir))
+        elif os.name == 'posix':
+            self.assertEqual(sysconfig.get_makefile_filename(), srcdir)
+
+    def test_srcdir_independent_of_cwd(self):
+        # srcdir should be independent of the current working directory
+        # See Issues #15322, #15364.
+        srcdir = sysconfig.get_config_var('srcdir')
+        cwd = os.getcwd()
+        try:
+            os.chdir('..')
+            srcdir2 = sysconfig.get_config_var('srcdir')
+        finally:
+            os.chdir(cwd)
+        self.assertEqual(srcdir, srcdir2)
+
 
 class MakefileTests(unittest.TestCase):
 

Misc/NEWS

@@ -55,6 +55,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #15364: Fix sysconfig.get_config_var('srcdir') to be an
+  absolute path.
+
 - Issue #15041: update "see also" list in tkinter documentation.
 
 - Issue #15413: os.times() had disappeared under Windows.