Use the stack_trace library in scheduled_test.

pkg/scheduled_test/lib/src/utils.dart

Index: pkg/scheduled_test/lib/src/utils.dart
diff --git a/pkg/scheduled_test/lib/src/utils.dart b/pkg/scheduled_test/lib/src/utils.dart
index 57c341d888d021bf454f006991a6ac50af5ac646..419e47eb8bc30e224f997cd5920922b9f844a36d 100644
--- a/pkg/scheduled_test/lib/src/utils.dart
+++ b/pkg/scheduled_test/lib/src/utils.dart
@@ -6,6 +6,8 @@ library utils;
 
 import 'dart:async';
 
+import 'package:stack_trace/stack_trace.dart';
+
 /// A pair of values.
 class Pair<E, F> {
   E first;
@@ -182,3 +184,12 @@ bool fullMatch(String string, Pattern pattern) {
   if (matches.isEmpty) return false;
   return matches.first.start == 0 && matches.first.end == string.length;
 }
+
+/// Returns a string representation of [trace] that has the core and test frames
+/// folded together.
+String terseTraceString(StackTrace trace) {
+  return new Trace.from(trace).terse.foldFrames((frame) {
+    return frame.package == 'scheduled_test' || frame.package == 'unittest' ||
+        frame.isCore;
+  }).toString().trim();
+}