Fix more pub bugs.

sdk/lib/_internal/pub/lib/src/command.dart

Index: sdk/lib/_internal/pub/lib/src/command.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command.dart b/sdk/lib/_internal/pub/lib/src/command.dart
index 6bc10b0e2fc99d0349bb09569da759bee37b57a4..5f0df64ae1daee3acc16c1d281e46c36e43b54da 100644
--- a/sdk/lib/_internal/pub/lib/src/command.dart
+++ b/sdk/lib/_internal/pub/lib/src/command.dart
@@ -227,6 +227,11 @@ abstract class PubCommand {
     }
   }
 
+  /// Fails with a usage error [message] for this command.
+  void usageError(String message) {

[nweiz, 2014/07/07 19:57:18]

Does this shadow [usageError] in utils? That seems weird. Where is it important
that we eagerly bind the usage? Can we do this explicitly there?

[Bob Nystrom, 2014/07/07 21:02:59]

Yeah. :(
The help command and the top level command routing code both throw usageErrors()
for specific command objects. For the former, you want usage for the failed
command, not the help command itself. For the latter, you aren't inside a
command, so the lazy binding won't happen.

I think the right thing to do is ditch the lazy usage binding I added. I did
that so that you could throw a usageError() outside of the context of a command
(in executable.dart), but I think it's simpler to just pass in the command to
that.

I'll send out a patch.

+    throw new UsageException(message)..bindUsage(_getUsage());
+  }
+
   /// Generates a string of usage information for this command.
   String _getUsage() {
     var buffer = new StringBuffer();