Index: Python/traceback.c
===================================================================
--- Python/traceback.c	(revision 76445)
+++ Python/traceback.c	(working copy)
@@ -194,6 +194,7 @@
 {
 	int err = 0;
 	int fd;
+	struct stat st;
 	int i;
 	char *found_encoding;
 	char *encoding;
@@ -205,6 +206,7 @@
 	const int open_flags = O_RDONLY;
 #endif
 	char buf[MAXPATHLEN+1];
+	char linebuf[1000];
 	Py_UNICODE *u, *p;
 	Py_ssize_t len;
 
@@ -213,7 +215,19 @@
 		return 0;
 	Py_BEGIN_ALLOW_THREADS
 	fd = open(filename, open_flags);
+	if (fd >= 0) {
+		err = fstat(fd, &st);
+	}
 	Py_END_ALLOW_THREADS
+	if (fd >= 0 && err == 0 && S_ISDIR(st.st_mode)) {
+		close(fd);
+		PyOS_snprintf(linebuf, sizeof(linebuf), "    [Errno %d] %s: '%.500s'\n",
+			EISDIR, strerror(EISDIR), filename);
+		err = PyFile_WriteString(linebuf, f);
+		if (err != 0)
+			return err;
+		return 0;
+	}
 	if (fd < 0) {
 		fd = _Py_FindSourceFile(filename, buf, sizeof(buf), open_flags);
 		if (fd < 0)
Index: Lib/linecache.py
===================================================================
--- Lib/linecache.py	(revision 76445)
+++ Lib/linecache.py	(working copy)
@@ -11,6 +11,15 @@
 
 __all__ = ["getline", "clearcache", "checkcache"]
 
+class ErrorLineCache:
+    def __init__(self, str):
+        self.str = str
+    def __getitem__(self, key):
+        return self.str
+    def __len__(self):
+        return sys.maxsize
+
+
 def getline(filename, lineno, module_globals=None):
     lines = getlines(filename, module_globals)
     if 1 <= lineno <= len(lines):
@@ -38,7 +47,10 @@
     if filename in cache:
         return cache[filename][2]
     else:
-        return updatecache(filename, module_globals)
+        try:
+            return updatecache(filename, module_globals)
+        except Exception as e:
+            return ErrorLineCache(str(e))
 
 
 def checkcache(filename=None):
Index: Lib/test/test_traceback.py
===================================================================
--- Lib/test/test_traceback.py	(revision 76445)
+++ Lib/test/test_traceback.py	(working copy)
@@ -276,6 +276,19 @@
         self.assertTrue('inner_raise() # Marker' in blocks[2])
         self.check_zero_div(blocks[2])
 
+    def test_bad_file(self):
+        try:
+            exec(compile("spam()", ".", "exec"))
+        except Exception as _:
+            e = _
+        lines = self.get_report(e).splitlines()
+        self.assertEquals(len(lines), 6)
+        self.assertTrue(lines[0].startswith('Traceback'))
+        self.assertTrue(lines[1].startswith('  File'))
+        self.assertTrue('exec(compile(' in lines[2])
+        self.assertTrue(lines[3].startswith('  File'))
+        self.assertTrue('[Errno' in lines[4])
+        self.assertTrue(lines[5].startswith('NameError'))
 
 
 class PyExcReportingTests(BaseExceptionReportingTests, unittest.TestCase):