gh-154387: Fix structseq_repr mislabeling of unnamed PyStructSequence fields

Lib/test/test_structseq.py

@@ -48,6 +48,15 @@ def test_repr(self):
         self.assertIn("st_ino=", rep)
         self.assertIn("st_dev=", rep)
 
+        # Issue #154387: unnamed fields should not be mislabeled with named field names.
+        st = os.stat_result(range(10))
+        rep = repr(st)
+        self.assertEqual(
+            rep,
+            "os.stat_result(st_mode=0, st_ino=1, st_dev=2, st_nlink=3, "
+            "st_uid=4, st_gid=5, st_size=6, 7, 8, 9)"
+        )
+
     def test_concat(self):
         t1 = time.gmtime()
         t2 = t1 + tuple(t1)

Misc/NEWS.d/next/Core_and_Builtins/2026-07-22-13-35-00.gh-issue-154387.abc123.rst

@@ -0,0 +1 @@
+Fix :c:func:`structseq_repr` mislabeling unnamed :c:type:`PyStructSequence` fields. Patch by Pranav Choudhary.

Objects/structseq.c

@@ -305,20 +305,23 @@ structseq_repr(PyObject *op)
         }
 
         // Write name
-        const char *name_utf8 = typ->tp_members[i].name;
-        if (name_utf8 == NULL) {
-            PyErr_Format(PyExc_SystemError,
-                         "In structseq_repr(), member %zd name is NULL"
-                         " for type %.500s", i, typ->tp_name);
-            goto error;
-        }
-        if (PyUnicodeWriter_WriteUTF8(writer, name_utf8, -1) < 0) {
-            goto error;
+        const char *name_utf8 = NULL;
+        Py_ssize_t expected_offset = offsetof(PyStructSequence, ob_item) + i * sizeof(PyObject*);
+        for (Py_ssize_t k = 0; typ->tp_members[k].name != NULL; k++) {
+            if (typ->tp_members[k].offset == expected_offset) {
+                name_utf8 = typ->tp_members[k].name;
+                break;
+            }
         }
 
-        // Write "=" + repr(value)
-        if (PyUnicodeWriter_WriteChar(writer, '=') < 0) {
-            goto error;
+        if (name_utf8 != NULL) {
+            if (PyUnicodeWriter_WriteUTF8(writer, name_utf8, -1) < 0) {
+                goto error;
+            }
+            // Write "="
+            if (PyUnicodeWriter_WriteChar(writer, '=') < 0) {
+                goto error;
+            }
         }
         PyObject *value = PyStructSequence_GetItem((PyObject*)obj, i);
         assert(value != NULL);

PCbuild/readme.txt

@@ -23,7 +23,7 @@ external dependencies. To build, simply run the "build.bat" script without
 any arguments. After this succeeds, you can open the "pcbuild.sln"
 solution in Visual Studio to continue development.
 
-To build an installer package, refer to the README in the Tools/msi folder.
+To build an installer package, refer to PC/layout.
 
 The solution currently supports two platforms.  The Win32 platform is
 used to build standard x86-compatible 32-bit binaries, output into the
@@ -140,12 +140,6 @@ CPython in different ways:
 pythonw
     pythonw.exe, a variant of python.exe that doesn't open a Command
     Prompt window
-pylauncher
-    py.exe, the Python Launcher for Windows, see
-        https://docs.python.org/3/using/windows.html#launcher
-pywlauncher
-    pyw.exe, a variant of py.exe that doesn't open a Command Prompt
-    window
 _testembed
     _testembed.exe, a small program that embeds Python for testing
     purposes, used by test_capi.py
@@ -156,8 +150,6 @@ _freeze_module
     _freeze_module.exe, used to regenerate frozen modules in Python
     after changes have been made to the corresponding source files
     (e.g. Lib\importlib\_bootstrap.py).
-pyshellext
-    pyshellext.dll, the shell extension deployed with the launcher
 python3dll
     python3.dll, the PEP 384 Stable ABI dll
     (not installed on free-threaded builds)
@@ -247,7 +239,7 @@ _sqlite3
         https://www.sqlite.org/
 
 _tkinter
-    Wraps version 9.0.3 of the Tk windowing system, which is downloaded
+    Wraps version 9.0.4 of the Tk windowing system, which is downloaded
     from our binaries repository at
     https://github.com/python/cpython-bin-deps.
 
@@ -420,8 +412,6 @@ _testclinic_limited extension, the file Modules/_testclinic_limited.c:
 * Save and exit Visual Studio.
 * Add `;_testclinic_limited` to `<TestModules Include="...">` in
   PCbuild\pcbuild.proj.
-* Update "exts" in Tools\msi\lib\lib_files.wxs file or in
-  Tools\msi\test\test_files.wxs file (for tests).
 * PC\layout\main.py needs updating if you add a test-only extension whose name
   doesn't start with "_test".
 * Add the extension to PCbuild\readme.txt (this file).