Lazily load the entrypoint.

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 c37dc1cad361f2db69714010dec4d526c057a7f0..0b3e985bb2ba83de6dedacc646630903088e1367 100644
--- a/sdk/lib/_internal/pub/lib/src/command.dart
+++ b/sdk/lib/_internal/pub/lib/src/command.dart
@@ -109,7 +109,17 @@ abstract class PubCommand {
   ArgResults get commandOptions => _commandOptions;
   ArgResults _commandOptions;
 
-  Entrypoint entrypoint;
+  /// Gets the [Entrypoint] package for the current working directory.
+  ///
+  /// This will load the pubspec and fail with an error if the current directory
+  /// is not a package.
+  Entrypoint get entrypoint {
+    // Lazy load it.
+    if (_entrypoint == null) _entrypoint = new Entrypoint(path.current, _cache);
+    return _entrypoint;
+  }
+
+  Entrypoint _entrypoint;
 
   /// A one-line description of this command.
   String get description;
@@ -130,12 +140,6 @@ abstract class PubCommand {
   /// The URL for web documentation for this command.
   String get docUrl => null;
 
-  /// Whether or not this command requires [entrypoint] to be defined.
-  ///
-  /// If false, pub won't look for a pubspec and [entrypoint] will be null when
-  /// the command runs. This only needs to be set in leaf commands.
-  bool get requiresEntrypoint => true;
-
   /// Whether or not this command takes arguments in addition to options.
   ///
   /// If false, pub will exit with an error if arguments are provided. This
@@ -184,13 +188,6 @@ abstract class PubCommand {
     _cache = new SystemCache.withSources(cacheDir, isOffline: isOffline);
     _globals = new GlobalPackages(_cache);
 
-    if (requiresEntrypoint) {
-      // 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.
-      entrypoint = new Entrypoint(path.current, cache);
-    }
-
     return syncFuture(onRun);
   }