Move pub into sdk/lib/_internal.

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

Index: sdk/lib/_internal/pub/lib/src/sdk.dart
diff --git a/utils/pub/sdk.dart b/sdk/lib/_internal/pub/lib/src/sdk.dart
similarity index 92%
rename from utils/pub/sdk.dart
rename to sdk/lib/_internal/pub/lib/src/sdk.dart
index b9b50ecca2c7a1c2867fa340f81e734701292897..6b304d9e4cadb0623658d1e414dcf992566496f1 100644
--- a/utils/pub/sdk.dart
+++ b/sdk/lib/_internal/pub/lib/src/sdk.dart
@@ -28,10 +28,8 @@ String get rootDirectory {
     return dir;
   }
 
-  var pubDir = path.dirname(new Options().script);
-  dir = path.normalize(path.join(pubDir, "../../"));
-  log.fine("Located SDK at $dir");
-  return dir;
+  throw new Exception('DART_SDK environment variable not set, unable to find '
+      'the SDK.');

[Bob Nystrom, 2013/04/23 19:41:19]

Can you get the automatic detection working? Having to pass this in is a pain.
The shell script still does for historical reasons, but there are other cases
where it isn't provided, I think. (For example, running a non-integration test
suite like version_solver.)

[nweiz, 2013/04/23 19:56:27]

This code was broken; it would return the repo root, which doesn't contain
anything pub expects from the SDK. I'm pretty sure it was never being run.

I can probably find a way to detect the SDK even when DART_SDK isn't passed, but
I'm reluctant to add dead code.

[Bob Nystrom, 2013/04/23 20:26:14]

I'm fine with leaving it out for now then.

 }
 
 /// Gets the SDK's revision number formatted to be a semantic version.