Fix error detection for a non-existent global script.

test/global/run/nonexistent_script_test.dart

Index: test/global/run/nonexistent_script_test.dart
diff --git a/test/global/run/nonexistent_script_test.dart b/test/global/run/nonexistent_script_test.dart
index db7f099c190d84bb94be921be6a95913aeeae538..845717475168ab555c04f027c3a0aa8808a3c779 100644
--- a/test/global/run/nonexistent_script_test.dart
+++ b/test/global/run/nonexistent_script_test.dart
@@ -9,12 +9,17 @@ import '../../test_pub.dart';
 
 main() {
   integration('errors if the script does not exist.', () {
-    servePackages((builder) => builder.serve("foo", "1.0.0"));
+    servePackages((builder) => builder.serve("foo", "1.0.0", pubspec: {
+      // Make sure barback doesn't try to look at *all* dependencies when
+      // determining which transformers to load.
+      "dev_dependencies": {"bar": "1.0.0"}
+    }));
 
     schedulePub(args: ["global", "activate", "foo"]);
 
     var pub = pubRun(global: true, args: ["foo:script"]);
-    pub.stderr.expect("Could not find ${p.join("bin", "script.dart")}.");
+    pub.stderr.expect(
+        "Could not find ${p.join("bin", "script.dart")} in package foo.");
     pub.shouldExit(exit_codes.NO_INPUT);
   });
 }