Exit with an error on unexpected command line arguments.

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

Index: sdk/lib/_internal/pub/lib/src/command/uploader.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command/uploader.dart b/sdk/lib/_internal/pub/lib/src/command/uploader.dart
index c3160ee18054db032d8223d305101d841a4704ec..32e21a84be332aaa49c766a7bbd04fe681aec640 100644
--- a/sdk/lib/_internal/pub/lib/src/command/uploader.dart
+++ b/sdk/lib/_internal/pub/lib/src/command/uploader.dart
@@ -22,6 +22,7 @@ class UploaderCommand extends PubCommand {
   final description = "Manage uploaders for a package on pub.dartlang.org.";
   final usage = "pub uploader [options] {add/remove} <email>";
   final requiresEntrypoint = false;
+  bool get takesArguments => true;
 
   /// The URL of the package hosting server.
   Uri get server => Uri.parse(commandOptions['server']);
@@ -43,6 +44,7 @@ class UploaderCommand extends PubCommand {
 
     var rest = commandOptions.rest.toList();
 
+    // TODO(rnystrom): Use subcommands for these.
     var command = rest.removeAt(0);
     if (!['add', 'remove'].contains(command)) {
       log.error('Unknown uploader command "$command".');