Fix error detection for a non-existent global script.

lib/src/executable.dart

Index: lib/src/executable.dart
diff --git a/lib/src/executable.dart b/lib/src/executable.dart
index bd21b4d8301e0d90739eb64b9598455fb9387ac7..83880392dfb02f8828d8215ebf3cc4636735d506 100644
--- a/lib/src/executable.dart
+++ b/lib/src/executable.dart
@@ -105,7 +105,7 @@ Future<int> runExecutable(Entrypoint entrypoint, String package,
 
   if (executableUrl == null) {
     var message = "Could not find ${log.bold(executable)}";
-    if (package != entrypoint.root.name) {
+    if (isGlobal || package != entrypoint.root.name) {
       message += " in package ${log.bold(package)}";
     }
     log.error("$message.");