gh-123596: Add missing tracebacklimit attribute to sys module

Include/internal/pycore_traceback.h

@@ -8,6 +8,9 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+/* Maximum number of error tracebacks to print */
+#define PyTraceBack_LIMIT 1000
+
 // Export for '_ctypes' shared extension
 PyAPI_FUNC(int) _Py_DisplaySourceLine(PyObject *, PyObject *, int, int, int *, PyObject **);
 

Lib/test/test_sys.py

@@ -1187,6 +1187,9 @@ def check(tracebacklimit, expected):
             b'    ~~^~~',
             b'ZeroDivisionError: division by zero'
         ]
+        self.assertTrue(hasattr(sys, "tracebacklimit"),
+                        'tracebacklimit attribute does not exist')
+        self.assertEqual(getattr(sys, 'tracebacklimit', 1_000), 1_000)
         check(10, traceback)
         check(3, traceback)
         check(2, traceback[:1] + traceback[4:])

Misc/NEWS.d/next/Library/2024-10-20-11-45-50.gh-issue-123596.HONVYS.rst

@@ -0,0 +1 @@
+Fix non-existent :attr:`sys.tracebacklimit` in :mod:`sys`. Patch by RUANG.

Python/sysmodule.c

@@ -35,6 +35,7 @@ Data members:
 #include "pycore_structseq.h"     // _PyStructSequence_InitBuiltinWithFlags()
 #include "pycore_sysmodule.h"     // export _PySys_GetSizeOf()
 #include "pycore_tuple.h"         // _PyTuple_FromArray()
+#include "pycore_traceback.h"     // PyTraceBack_LIMIT
 
 #include "pydtrace.h"             // PyDTrace_AUDIT()
 #include "osdefs.h"               // DELIM
@@ -3666,6 +3667,8 @@ _PySys_UpdateConfig(PyThreadState *tstate)
         COPY_LIST("path", config->module_search_paths);
     }
 
+    SET_SYS("tracebacklimit", PyLong_FromLong(PyTraceBack_LIMIT));
+
     COPY_WSTR("executable", config->executable);
     COPY_WSTR("_base_executable", config->base_executable);
     COPY_WSTR("prefix", config->prefix);

Python/traceback.c

@@ -704,8 +704,6 @@ tb_printinternal(PyTracebackObject *tb, PyObject *f, long limit)
     return -1;
 }
 
-#define PyTraceBack_LIMIT 1000
-
 int
 _PyTraceBack_Print(PyObject *v, const char *header, PyObject *f)
 {