command: Fix 0.12upgrade stub

command/012_config_upgrade.go

@@ -1,6 +1,9 @@
 package command
 
-import "fmt"
+import (
+	"fmt"
+	"strings"
+)
 
 type ZeroTwelveUpgradeCommand struct {
 	Meta
@@ -13,3 +16,18 @@ v0.12 to upgrade your configuration syntax before upgrading to the current
 version.`))
 	return 0
 }
+
+func (c *ZeroTwelveUpgradeCommand) Help() string {
+	helpText := `
+Usage: terraform 0.12upgrade
+
+  The 0.12upgrade command is deprecated. You must run this command with
+  Terraform v0.12 to upgrade your configuration syntax before upgrading to
+  the current version.
+`
+	return strings.TrimSpace(helpText)
+}
+
+func (c *ZeroTwelveUpgradeCommand) Synopsis() string {
+	return "Rewrites pre-0.12 module source code for v0.12"
+}

commands.go

@@ -311,7 +311,7 @@ func initCommands(config *cliconfig.Config, services *disco.Disco, providerSrc g
 		//-----------------------------------------------------------
 
 		"0.12upgrade": func() (cli.Command, error) {
-			return &command.ZeroThirteenUpgradeCommand{
+			return &command.ZeroTwelveUpgradeCommand{
 				Meta: meta,
 			}, nil
 		},