Add Bob's path library to pub.

utils/pub/pub.dart

Index: utils/pub/pub.dart
diff --git a/utils/pub/pub.dart b/utils/pub/pub.dart
index 1daf20d4613c2ffe833b161b393fdf620f8952c8..12f40532fe5235e4a1bfe60c0a40f96179109790 100644
--- a/utils/pub/pub.dart
+++ b/utils/pub/pub.dart
@@ -19,6 +19,7 @@ import 'command_version.dart';
 import 'entrypoint.dart';
 import 'exit_codes.dart' as exit_codes;
 import 'package.dart';
+import 'path.dart' as path;
 import 'pubspec.dart';
 import 'source.dart';
 import 'source_registry.dart';
@@ -216,7 +217,7 @@ abstract class PubCommand {
       // TODO(rnystrom): Will eventually need better logic to walk up
       // subdirectories until we hit one that looks package-like. For now, just
       // assume the cwd is it.
-      future = Entrypoint.load(currentWorkingDir, cache);
+      future = Entrypoint.load(path.current, cache);
     }
 
     future = future.chain((entrypoint) {
@@ -237,10 +238,10 @@ abstract class PubCommand {
     future.handleException((e) {
       if (e is PubspecNotFoundException && e.name == null) {
         e = 'Could not find a file named "pubspec.yaml" in the directory '
-          '$currentWorkingDir.';
+          '${path.current}.';
       } else if (e is PubspecHasNoNameException && e.name == null) {
         e = 'pubspec.yaml is missing the required "name" field (e.g. "name: '
-          '${basename(currentWorkingDir)}").';
+          '${basename(path.current)}").';
       }
 
       handleError(e, future.stackTrace);