Don't skip tests on machines without git.

sdk/lib/_internal/pub/test/test_pub.dart

 // Copyright (c) 2013, 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.
 
 /// Test infrastructure for testing pub. Unlike typical unit tests, most pub
 /// tests are integration tests that stage some stuff on the file system, run
 /// pub, and then validate the results. This library provides an API to build
 /// tests like that.
 library test_pub;
 
@@ skipping 28 matching lines @@
 import 'descriptor.dart' as d;
 
 /// This should be called at the top of a test file to set up an appropriate
 /// test configuration for the machine running the tests.
 initConfig() {
   useCompactVMConfiguration();
   filterStacks = true;
   unittestConfiguration.timeout = null;
 }
 
-/// Returns whether we're running on a Dart build bot.
-bool get runningOnBuildbot =>
-  Platform.environment.containsKey('BUILDBOT_BUILDERNAME');
-
 /// The current [HttpServer] created using [serve].
 var _server;
 
 /// The list of paths that have been requested from the server since the last
 /// call to [getRequestedPaths].
 final _requestedPaths = <String>[];
 
 /// The cached value for [_portCompleter].
 Completer<int> _portCompleterCache;
 
@@ skipping 512 matching lines @@
 
     var pair = tee(_stderr);
     _stderr = pair.first;
     return pair.last;
   }
 }
 
 /// The path to the `packages` directory from which pub loads its dependencies.
 String get _packageRoot => path.absolute(Platform.packageRoot);
 
-/// Skips the current test if Git is not installed. This validates that the
-/// current test is running on a buildbot in which case we expect git to be
-/// installed. If we are not running on the buildbot, we will instead see if
-/// git is installed and skip the test if not. This way, users don't need to
-/// have git installed to run the tests locally (unless they actually care
-/// about the pub git tests).
+/// Fails the current test if Git is not installed.
 ///
-/// This will also increase the [Schedule] timeout to 30 seconds on Windows,
+/// We require machines running these tests to have git installed. This
+/// validation gives an easier-to-understand error when that requirement isn't
+/// met than just failing in the middle of a test when pub invokes git.
+///
+/// This also increases the [Schedule] timeout to 30 seconds on Windows,
 /// where Git runs really slowly.
 void ensureGit() {
   if (Platform.operatingSystem == "windows") {
     currentSchedule.timeout = new Duration(seconds: 30);
   }
 
   schedule(() {
     return gitlib.isInstalled.then((installed) {
-      if (installed) return;
-      if (runningOnBuildbot) return;
-      currentSchedule.abort();
+      if (!installed) {
+        throw new Exception("Git must be installed to run this test.");
+      }
     });
   }, 'ensuring that Git is installed');
 }
 
 /// Create a lock file for [package] without running `pub get`.
 ///
 /// This creates a lock file with only path dependencies. [sandbox] is a list of
 /// dependencies to be found in the sandbox directory. [pkg] is a list of
 /// packages in the Dart repo's "pkg" directory; each package listed here and
 /// all its dependencies will be linked to the version in the Dart repo.
@@ skipping 222 matching lines @@
   bool matches(item, Map matchState) {
     if (item is! Pair) return false;
     return _firstMatcher.matches(item.first, matchState) &&
         _lastMatcher.matches(item.last, matchState);
   }
 
   Description describe(Description description) {
     description.addAll("(", ", ", ")", [_firstMatcher, _lastMatcher]);
   }
 }