Start pulling pub from its own repo.

sdk/lib/_internal/pub/test/get/path/shared_dependency_symlink_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 d.file.
-
-import 'package:path/path.dart' as path;
-
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration("shared dependency with symlink", () {
-    d.dir("shared", [
-      d.libDir("shared"),
-      d.libPubspec("shared", "0.0.1")
-    ]).create();
-
-    d.dir("foo", [
-      d.libDir("foo"),
-      d.libPubspec("foo", "0.0.1", deps: {
-        "shared": {"path": "../shared"}
-      })
-    ]).create();
-
-    d.dir("bar", [
-      d.libDir("bar"),
-      d.libPubspec("bar", "0.0.1", deps: {
-        "shared": {"path": "../link/shared"}
-      })
-    ]).create();
-
-    d.dir(appPath, [
-      d.appPubspec({
-        "foo": {"path": "../foo"},
-        "bar": {"path": "../bar"}
-      })
-    ]).create();
-
-    d.dir("link").create();
-    scheduleSymlink("shared", path.join("link", "shared"));
-
-    pubGet();
-
-    d.dir(packagesPath, [
-      d.dir("foo", [d.file("foo.dart", 'main() => "foo";')]),
-      d.dir("bar", [d.file("bar.dart", 'main() => "bar";')]),
-      d.dir("shared", [d.file("shared.dart", 'main() => "shared";')])
-    ]).validate();
-  });
-}