anchor.diff:            "pkgB_b() { pkgA(); }");
   
         // Application.
  +      File('${tempDir.path}/app/.dart_tool/package_config.json')
  +        ..createSync(recursive: true)
  +        ..writeAsStringSync('''
  +  {
  +    "configVersion": 2,
  +    "packages": [
  +      {
  +        "name": "pkgA",
  +        "rootUri": "${tempDir.path}/pkgA",
  +        "packageUri": "./"
  +      },
  +      {
  +        "name": "pkgB",
  +        "rootUri": "${tempDir.path}/pkgB",
  +        "packageUri": "./"
  +      }
  +    ]
  +  }
  +''');
         file = File('${tempDir.path}/app/.packages')..createSync(recursive: true);
         file.writeAsStringSync("pkgA:../pkgA\n"
             "pkgB:../pkgB");
  
positive.code:       file.writeAsStringSync("pkgA() {}");
  
        // Package B.
        file = File('${tempDir.path}/pkgB/.packages')
          ..createSync(recursive: true);
        file.writeAsStringSync("pkgA: ../pkgA");
        file = File('${tempDir.path}/pkgB/a.dart')..createSync(recursive: true);
        file.writeAsStringSync("pkgB_a() {}");
        file = File('${tempDir.path}/pkgB/b.dart')..createSync(recursive: true);
  
negative.code:       file.writeAsStringSync("pkgA() {}");
  
        // Package B.
        file = File('${tempDir.path}/pkgB/a.dart')..createSync(recursive: true);
        file.writeAsStringSync("pkgB_a() {}");
        file = File('${tempDir.path}/pkgB/b.dart')..createSync(recursive: true);
  