Don't show a stack trace on a bad path dependency path.

sdk/lib/_internal/pub/test/install/path/nonexistent_dir_test.dart

Index: sdk/lib/_internal/pub/test/install/path/nonexistent_dir_test.dart
diff --git a/sdk/lib/_internal/pub/test/install/path/nonexistent_dir_test.dart b/sdk/lib/_internal/pub/test/install/path/nonexistent_dir_test.dart
index 7220cb9c151c4725333981c26eaf2d0140737e4f..053c9225ad8922471c05c6991e125a46c1203320 100644
--- a/sdk/lib/_internal/pub/test/install/path/nonexistent_dir_test.dart
+++ b/sdk/lib/_internal/pub/test/install/path/nonexistent_dir_test.dart
@@ -7,7 +7,6 @@ import 'dart:io';
 import 'package:pathos/path.dart' as path;
 import 'package:scheduled_test/scheduled_test.dart';
 
-import '../../../lib/src/exit_codes.dart' as exit_codes;
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
@@ -34,6 +33,6 @@ main() {
     schedulePub(args: ['install'],
         error:
             new RegExp("Could not find package 'foo' at '$escapePath'."),
-        exitCode: exit_codes.DATA);
+        exitCode: 1);
   });
 }