cmd/cue: fix build

Fixes Issue #34

Change-Id: Ib0474b79ed0aee706c6a981c9aaa431f4ca991ae
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/1820
Reviewed-by: Marcel van Lohuizen <mpvl@google.com>
diff --git a/cmd/cue/cmd/root.go b/cmd/cue/cmd/root.go
index 84d8a45..a705c0c 100644
--- a/cmd/cue/cmd/root.go
+++ b/cmd/cue/cmd/root.go
@@ -157,6 +157,7 @@
 	fPackage  = rootCmd.PersistentFlags().StringP("package", "p", "", "CUE package to evaluate")
 	fSimplify = rootCmd.PersistentFlags().BoolP("simplify", "s", false, "simplify output")
 	fIgnore   = rootCmd.PersistentFlags().BoolP("ignore", "i", false, "proceed in the presence of errors")
+	fVerbose  = rootCmd.PersistentFlags().BoolP("verbose", "v", false, "print information about progress")
 )
 
 // initConfig reads in config file and ENV variables if set.