Index: lldb/packages/Python/lldbsuite/test/lldbutil.py
===================================================================
--- lldb/packages/Python/lldbsuite/test/lldbutil.py
+++ lldb/packages/Python/lldbsuite/test/lldbutil.py
@@ -840,6 +840,12 @@
             threads.append(thread)
     return threads
 
+def get_thread_overview(test):
+    """Returns a string providing an overview over all current threads.
+    Should be used for making test errors more expressive."""
+    test.runCmd("thread backtrace all")
+    return "Current threads:\n" + test.res.GetOutput()
+
 # Helper functions for run_to_{source,name}_breakpoint:
 
 def run_to_breakpoint_make_target(test, exe_name = "a.out", in_cwd = True):
@@ -897,9 +903,13 @@
 
     num_threads = len(threads)
     if only_one_thread:
-        test.assertEqual(num_threads, 1, "Expected 1 thread to stop at breakpoint, %d did."%(num_threads))
+        test.assertEqual(num_threads, 1,
+                         "Expected 1 thread to stop at breakpoint, %d did.\n%s"
+                         % (num_threads, get_thread_overview(test)))
     else:
-        test.assertGreater(num_threads, 0, "No threads stopped at breakpoint")
+        test.assertGreater(num_threads, 0,
+                           "No threads stopped at breakpoint.\n%s" %
+                           (get_thread_overview(test)))
 
     thread = threads[0]
     return (target, process, thread, bkpt)