#5287: Add exception handling around findCaller() call to help out IronPython.

Lib/logging/__init__.py

@@ -1128,7 +1128,12 @@ class Logger(Filterer):
         all the handlers of this logger to handle the record.
         """
         if _srcfile:
+            #IronPython doesn't track Python frames, so findCaller throws an
+            #exception. We trap it here so that IronPython can use logging.
+            try:
                 fn, lno, func = self.findCaller()
+            except ValueError:
+                fn, lno, func = "(unknown file)", 0, "(unknown function)"
         else:
             fn, lno, func = "(unknown file)", 0, "(unknown function)"
         if exc_info:

Misc/NEWS

@@ -161,6 +161,8 @@ Core and Builtins
 
 Library
 -------
+- Issue #5287: Add exception handling around findCaller() call to help out
+  IronPython.
 
 - Issue #5282: Fixed mmap resize on 32bit windows and unix. When offset > 0,
   The file was resized to wrong size.