puppet erb code fails

Question

I've written the following in my templates, but when I run puppet client it keeps complaining of "Failed to parse template Detail: Could not find value for 'mas". My problem is that ipa variable is empty of does not exist when doing this check, so why is mas.empty getting executed?

<% if !ipa.empty? %>
    <% if !mas.empty? %>address=<%= address %>
<% end -%>
<% end -%>

What tips are there for debugging this?

Thanks

Answer 1

I would just do:

<% if @ipa %>
  <% if @mas %>address=<%= @address %>
  <% end -%>
<% end -%>

The @ipa will be false if it isn't set (is empty), so the following code would not be executed.

I use this code a lot in my templates.