Index: Python/errors.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/errors.c,v
retrieving revision 2.75
diff -u -r2.75 errors.c
--- Python/errors.c	11 Dec 2002 14:04:59 -0000	2.75
+++ Python/errors.c	18 Feb 2003 22:51:43 -0000
@@ -600,18 +600,17 @@
 	Py_XDECREF(tb);
 }
 
+extern PyObject *PyModule_WarningsModule;
 
 /* Function to issue a warning message; may raise an exception. */
 int
 PyErr_Warn(PyObject *category, char *message)
 {
-	PyObject *mod, *dict, *func = NULL;
+	PyObject *dict, *func = NULL;
 
-	mod = PyImport_ImportModule("warnings");
-	if (mod != NULL) {
-		dict = PyModule_GetDict(mod);
+	if (PyModule_WarningsModule != NULL) {
+		dict = PyModule_GetDict(PyModule_WarningsModule);
 		func = PyDict_GetItemString(dict, "warn");
-		Py_DECREF(mod);
 	}
 	if (func == NULL) {
 		PySys_WriteStderr("warning: %s\n", message);
Index: Python/pythonrun.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/pythonrun.c,v
retrieving revision 2.177
diff -u -r2.177 pythonrun.c
--- Python/pythonrun.c	13 Feb 2003 22:07:59 -0000	2.177
+++ Python/pythonrun.c	18 Feb 2003 22:51:44 -0000
@@ -60,6 +60,11 @@
   true divisions (which they will be in 2.3). */
 int _Py_QnewFlag = 0;
 
+/* Reference to 'warnings' module, to avoid importing it
+   on the fly when the import lock may be held.  See 683658
+*/
+PyObject *PyModule_WarningsModule = NULL;
+
 static int initialized = 0;
 
 /* API to access the initialized flag -- useful for esoteric use */
@@ -169,6 +174,8 @@
 
 	_PyImportHooks_Init();
 
+	PyModule_WarningsModule = PyImport_ImportModule("warnings");
+
 	initsigs(); /* Signal handling stuff, including initintr() */
 
 	initmain(); /* Module __main__ */
@@ -224,6 +231,10 @@
 
 	/* Cleanup Codec registry */
 	_PyCodecRegistry_Fini();
+
+	/* drop module references we saved */
+	Py_XDECREF(PyModule_WarningsModule);
+	PyModule_WarningsModule = NULL;
 
 	/* Destroy all modules */
 	PyImport_Cleanup();
Index: Lib/warnings.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/warnings.py,v
retrieving revision 1.18
diff -u -r1.18 warnings.py
--- Lib/warnings.py	14 Oct 2002 21:06:02 -0000	1.18
+++ Lib/warnings.py	18 Feb 2003 22:51:44 -0000
@@ -1,6 +1,10 @@
 """Python part of the warnings subsystem."""
 
+# Note: function level imports should *not* be used
+# in this module as it may cause import lock deadlock.
+# See bug 683658.
 import sys, re, types
+import linecache
 
 __all__ = ["warn", "showwarning", "formatwarning", "filterwarnings",
            "resetwarnings"]
@@ -114,7 +118,6 @@
 
 def formatwarning(message, category, filename, lineno):
     """Function to format a warning the standard way."""
-    import linecache
     s =  "%s:%s: %s: %s\n" % (filename, lineno, category.__name__, message)
     line = linecache.getline(filename, lineno).strip()
     if line: