youknowone · Oct 18, 2026 · Oct 17, 2026 · Oct 17, 2026 · Oct 17, 2026 · Oct 17, 2026
diff --git a/Lib/_osx_support.py b/Lib/_osx_support.py
@@ -17,7 +17,8 @@
 _UNIVERSAL_CONFIG_VARS = ('CFLAGS', 'LDFLAGS', 'CPPFLAGS', 'BASECFLAGS',
                             'BLDSHARED', 'LDSHARED', 'CC', 'CXX',
                             'PY_CFLAGS', 'PY_LDFLAGS', 'PY_CPPFLAGS',
-                            'PY_CORE_CFLAGS', 'PY_CORE_LDFLAGS')
+                            'PY_CORE_CFLAGS', 'PY_CORE_LDFLAGS',
+                            'PY_CORE_EXE_LDFLAGS')
 
 # configuration variables that may contain compiler calls
 _COMPILER_CONFIG_VARS = ('BLDSHARED', 'LDSHARED', 'CC', 'CXX')

diff --git a/Lib/sysconfig/__init__.py b/Lib/sysconfig/__init__.py
@@ -412,7 +412,13 @@ def _init_non_posix(vars):
     vars['EXE'] = '.exe'
     vars['VERSION'] = _PY_VERSION_SHORT_NO_DOT
     vars['BINDIR'] = os.path.dirname(_safe_realpath(sys.executable))
-    vars['TZPATH'] = ''
+    # No standard path exists on Windows for this, but we'll check
+    # whether someone is imitating a POSIX-like layout
+    check_tzpath = os.path.join(vars['prefix'], 'share', 'zoneinfo')
+    if os.path.exists(check_tzpath):
+        vars['TZPATH'] = check_tzpath
+    else:
+        vars['TZPATH'] = ''
 
 #
 # public APIs
@@ -431,6 +437,7 @@ def parse_config_h(fp, vars=None):
     import re
     define_rx = re.compile("#define ([A-Z][A-Za-z0-9_]+) (.*)\n")
     undef_rx = re.compile("/[*] #undef ([A-Z][A-Za-z0-9_]+) [*]/\n")
+    quoted_re = re.compile('^"(.*)"$')
 
     while True:
         line = fp.readline()
@@ -439,6 +446,8 @@ def parse_config_h(fp, vars=None):
         m = define_rx.match(line)
         if m:
             n, v = m.group(1, 2)
+            if mq := quoted_re.match(v):
+                v = mq.group(1)
             try:
                 if n in _ALWAYS_STR:
                     raise ValueError
@@ -639,6 +648,9 @@ def get_platform():
     isn't particularly important.
 
     Examples of returned values:
+       linux-x86_64
+       linux-aarch64
+       solaris-2.6-sun4u
 
 
     Windows:
@@ -656,12 +668,10 @@ def get_platform():
 
     For other non-POSIX platforms, currently just returns :data:`sys.platform`."""
     if os.name == 'nt':
-        if 'amd64' in sys.version.lower():
-            return 'win-amd64'
-        if '(arm)' in sys.version.lower():
-            return 'win-arm32'
-        if '(arm64)' in sys.version.lower():
-            return 'win-arm64'
+        import _sysconfig
+        platform = _sysconfig.get_platform()
+        if platform:
+            return platform
         return sys.platform
 
     if os.name != "posix" or not hasattr(os, 'uname'):

diff --git a/Lib/sysconfig/__main__.py b/Lib/sysconfig/__main__.py
@@ -21,8 +21,9 @@
 # Regexes needed for parsing Makefile (and similar syntaxes,
 # like old-style Setup files).
 _variable_rx = r"([a-zA-Z][a-zA-Z0-9_]+)\s*=\s*(.*)"
-_findvar1_rx = r"\$\(([A-Za-z][A-Za-z0-9_]*)\)"
-_findvar2_rx = r"\${([A-Za-z][A-Za-z0-9_]*)}"
+_findvar_rx = (r"\$(\([A-Za-z][A-Za-z0-9_]*\)"
+                 r"|\{[A-Za-z][A-Za-z0-9_]*\}"
+                 r"|\$?)")
 
 
 def _parse_makefile(filename, vars=None, keep_unresolved=True):
@@ -49,99 +50,72 @@ def _parse_makefile(filename, vars=None, keep_unresolved=True):
         m = re.match(_variable_rx, line)
         if m:
             n, v = m.group(1, 2)
-            v = v.strip()
-            # `$$' is a literal `$' in make
-            tmpv = v.replace('$$', '')
-
-            if "$" in tmpv:
-                notdone[n] = v
-            else:
-                try:
-                    if n in _ALWAYS_STR:
-                        raise ValueError
-
-                    v = int(v)
-                except ValueError:
-                    # insert literal `$'
-                    done[n] = v.replace('$$', '$')
-                else:
-                    done[n] = v
-
-    # do variable interpolation here
-    variables = list(notdone.keys())
+            notdone[n] = v.strip()
 
     # Variables with a 'PY_' prefix in the makefile. These need to
     # be made available without that prefix through sysconfig.
     # Special care is needed to ensure that variable expansion works, even
     # if the expansion uses the name without a prefix.
     renamed_variables = ('CFLAGS', 'LDFLAGS', 'CPPFLAGS')
 
-    while len(variables) > 0:
-        for name in tuple(variables):
-            value = notdone[name]
-            m1 = re.search(_findvar1_rx, value)
-            m2 = re.search(_findvar2_rx, value)
-            if m1 and m2:
-                m = m1 if m1.start() < m2.start() else m2
-            else:
-                m = m1 if m1 else m2
-            if m is not None:
-                n = m.group(1)
-                found = True
-                if n in done:
-                    item = str(done[n])
-                elif n in notdone:
-                    # get it on a subsequent round
-                    found = False
-                elif n in os.environ:
-                    # do it like make: fall back to environment
-                    item = os.environ[n]
-
-                elif n in renamed_variables:
-                    if (name.startswith('PY_') and
-                        name[3:] in renamed_variables):
-                        item = ""
-
-                    elif 'PY_' + n in notdone:
-                        found = False
-
-                    else:
-                        item = str(done['PY_' + n])
-
+    def resolve_var(name):
+        def repl(m):
+            n = m[1]
+            if n == '$':
+                return '$'
+            elif n == '':
+                # bogus variable reference (e.g. "prefix=$/opt/python")
+                if keep_unresolved:
+                    return m[0]
+                raise ValueError
+            elif n[0] == '(' and n[-1] == ')':
+                n = n[1:-1]
+            elif n[0] == '{' and n[-1] == '}':
+                n = n[1:-1]
+
+            if n in done:
+                return str(done[n])
+            elif n in notdone:
+                return str(resolve_var(n))
+            elif n in os.environ:
+                # do it like make: fall back to environment
+                return os.environ[n]
+            elif n in renamed_variables:
+                if name.startswith('PY_') and name[3:] in renamed_variables:
+                    return ""
+                n = 'PY_' + n
+                if n in notdone:
+                    return str(resolve_var(n))
                 else:
-                    done[n] = item = ""
-
-                if found:
-                    after = value[m.end():]
-                    value = value[:m.start()] + item + after
-                    if "$" in after:
-                        notdone[name] = value
-                    else:
-                        try:
-                            if name in _ALWAYS_STR:
-                                raise ValueError
-                            value = int(value)
-                        except ValueError:
-                            done[name] = value.strip()
-                        else:
-                            done[name] = value
-                        variables.remove(name)
-
-                        if name.startswith('PY_') \
-                        and name[3:] in renamed_variables:
-
-                            name = name[3:]
-                            if name not in done:
-                                done[name] = value
-
+                    assert n not in done
+                    return ""
             else:
-                # Adds unresolved variables to the done dict.
-                # This is disabled when called from distutils.sysconfig
-                if keep_unresolved:
-                    done[name] = value
-                # bogus variable reference (e.g. "prefix=$/opt/python");
-                # just drop it since we can't deal
-                variables.remove(name)
+                done[n] = ""
+                return ""
+
+        assert name not in done
+        done[name] = ""
+        try:
+            value = re.sub(_findvar_rx, repl, notdone[name])
+        except ValueError:
+            del done[name]
+            return ""
+        value = value.strip()
+        if name not in _ALWAYS_STR:
+            try:
+                value = int(value)
+            except ValueError:
+                pass
+        done[name] = value
+        if name.startswith('PY_') and name[3:] in renamed_variables:
+            name = name[3:]
+            if name not in done:
+                done[name] = value
+        return value
+
+    for n in notdone:
+        if n not in done:
+            resolve_var(n)
 
     # strip spurious spaces
     for k, v in done.items():

diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
@@ -1652,8 +1652,12 @@ def _platform_specific(self):
                 ))
 
             self._env = {k.upper(): os.getenv(k) for k in os.environ}
-            self._env["PYTHONHOME"] = os.path.dirname(self.real)
+            home = os.path.dirname(self.real)
             if sysconfig.is_python_build():
+                home = os.path.join(home, sysconfig.get_config_var('VPATH'))
+            self._env["PYTHONHOME"] = home
+            # TODO: RUSTPYTHON; Cargo builds do not use CPython's Modules/Setup.
+            if sys.implementation.name == 'rustpython':
                 self._env["PYTHONPATH"] = STDLIB_DIR
     else:
         def _platform_specific(self):

diff --git a/Lib/test/test__osx_support.py b/Lib/test/test__osx_support.py
@@ -25,7 +25,7 @@ def setUp(self):
             'CFLAGS', 'LDFLAGS', 'CPPFLAGS',
             'BASECFLAGS', 'BLDSHARED', 'LDSHARED', 'CC',
             'CXX', 'PY_CFLAGS', 'PY_LDFLAGS', 'PY_CPPFLAGS',
-            'PY_CORE_CFLAGS', 'PY_CORE_LDFLAGS'
+            'PY_CORE_CFLAGS', 'PY_CORE_LDFLAGS', 'PY_CORE_EXE_LDFLAGS'
         )
 
     def add_expected_saved_initial_values(self, config_vars, expected_vars):