Add debug-printing to file, and remove from test.

pkg/docgen/test/generate_json_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library docgen.generate_json_test;
 
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
 import 'package:scheduled_test/descriptor.dart' as d;
@@ skipping 21 matching lines @@
         d.matcherFile('index.txt', hasSortedLines),
         d.matcherFile('library_list.json', isJsonMap),
         d.matcherFile('test_lib-bar.C.json', isJsonMap),
         d.matcherFile('test_lib-bar.json', isJsonMap),
         d.matcherFile('test_lib-foo.B.json', isJsonMap),
         d.matcherFile('test_lib-foo.json', isJsonMap),
         d.matcherFile('test_lib.A.json', isJsonMap),
         d.matcherFile('test_lib.B.json', isJsonMap),
         d.matcherFile('test_lib.C.json', isJsonMap),
         d.matcherFile('test_lib.json', isJsonMap),
-    ]).validate()
-      // TODO(ajohnsen): Remove once the issue is resolved.
-      .catchError((e, s) {
-        print(e);
-        print(s);
-        print(p.join(d.defaultRoot, 'docs'));
-        exit(1);
-      });
-
+    ]).validate();
   });
 }