properly handle decode error

post-processor/vagrant-cloud/step_release_version.go

@@ -31,7 +31,10 @@ func (s *stepReleaseVersion) Run(state multistep.StateBag) multistep.StepAction
 
 	if err != nil || (resp.StatusCode != 200) {
 		cloudErrors := &VagrantCloudErrors{}
-		_ = decodeBody(resp, cloudErrors)
+		if err := decodeBody(resp, cloudErrors); err != nil {
+			state.Put("error", fmt.Errorf("Error parsing provider response: %s", err))
+			return multistep.ActionHalt
+		}
 		if strings.Contains(cloudErrors.FormatErrors(), "already been released") {
 			ui.Message("Not releasing version, already released")
 			return multistep.ActionContinue