Start pulling pub from its own repo.

sdk/lib/_internal/pub/test/global/activate/snapshots_git_executables_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.
-
-import 'package:scheduled_test/scheduled_test.dart';
-
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration('snapshots the executables for a Git repo', () {
-    ensureGit();
-
-    d.git('foo.git', [
-      d.libPubspec("foo", "1.0.0"),
-      d.dir("bin", [
-        d.file("hello.dart", "void main() => print('hello!');"),
-        d.file("goodbye.dart", "void main() => print('goodbye!');"),
-        d.file("shell.sh", "echo shell"),
-        d.dir("subdir", [
-          d.file("sub.dart", "void main() => print('sub!');")
-        ])
-      ])
-    ]).create();
-
-    schedulePub(args: ["global", "activate", "-sgit", "../foo.git"],
-        output: allOf([
-      contains('Precompiled foo:hello.'),
-      contains("Precompiled foo:goodbye.")
-    ]));
-
-    d.dir(cachePath, [
-      d.dir('global_packages', [
-        d.dir('foo', [
-          d.matcherFile('pubspec.lock', contains('1.0.0')),
-          d.dir('bin', [
-            d.matcherFile('hello.dart.snapshot', contains('hello!')),
-            d.matcherFile('goodbye.dart.snapshot', contains('goodbye!')),
-            d.nothing('shell.sh.snapshot'),
-            d.nothing('subdir')
-          ])
-        ])
-      ])
-    ]).validate();
-  });
-}