Close #14439: Python now prints the traceback on runpy failure at startup.

Misc/NEWS

@@ -10,6 +10,8 @@ What's New in Python 3.4.0 Alpha 1?
 Core and Builtins
 -----------------
 
+- Issue #14439: Python now prints the traceback on runpy failure at startup.
+
 - Issue #17469: Fix _Py_GetAllocatedBlocks() and sys.getallocatedblocks()
   when running on valgrind.
 
@@ -1053,7 +1055,7 @@ IDLE
 
 - Issue #6698: IDLE now opens just an editor window when configured to do so.
 
-- Issue #8900: Using keyboard shortcuts in IDLE to open a file no longer 
+- Issue #8900: Using keyboard shortcuts in IDLE to open a file no longer
   raises an exception.
 
 - Issue #6649: Fixed missing exit status in IDLE. Patch by Guilherme Polo.
@@ -1092,7 +1094,7 @@ IDLE
 
 - Issue #6698: IDLE now opens just an editor window when configured to do so.
 
-- Issue #8900: Using keyboard shortcuts in IDLE to open a file no longer 
+- Issue #8900: Using keyboard shortcuts in IDLE to open a file no longer
   raises an exception.
 
 - Issue #6649: Fixed missing exit status in IDLE. Patch by Guilherme Polo.

Modules/main.c

@@ -167,17 +167,20 @@ static int RunModule(wchar_t *modname, int set_argv0)
     runpy = PyImport_ImportModule("runpy");
     if (runpy == NULL) {
         fprintf(stderr, "Could not import runpy module\n");
+        PyErr_Print();
         return -1;
     }
     runmodule = PyObject_GetAttrString(runpy, "_run_module_as_main");
     if (runmodule == NULL) {
         fprintf(stderr, "Could not access runpy._run_module_as_main\n");
+        PyErr_Print();
         Py_DECREF(runpy);
         return -1;
     }
     module = PyUnicode_FromWideChar(modname, wcslen(modname));
     if (module == NULL) {
         fprintf(stderr, "Could not convert module name to unicode\n");
+        PyErr_Print();
         Py_DECREF(runpy);
         Py_DECREF(runmodule);
         return -1;
@@ -186,6 +189,7 @@ static int RunModule(wchar_t *modname, int set_argv0)
     if (runargs == NULL) {
         fprintf(stderr,
             "Could not create arguments for runpy._run_module_as_main\n");
+        PyErr_Print();
         Py_DECREF(runpy);
         Py_DECREF(runmodule);
         Py_DECREF(module);