Hey Tom,
The error message in the crash log, undefined method `render', suggests that the Rendering helper isn’t activated. In a file in lib/ (e.g. lib/helpers.rb) you’ll need
use_helper Nanoc::Helpers::Rendering
or
include Nanoc::Helpers::Rendering
The render method is provided by the Rendering helper. Let me know if that helps, and if it doesn’t, do share the contents of your default layout file as well.
As for your question: It would be possible to start the crash log with the name of the item that is being compiled (it’s currently further down, in the ITEM BEING COMPILED section) but I’ve found that to be not a useful place to start — most often, when compilation fails, the stack trace provides more useful information.
Best,
Denis Defreyne
[dəˈni] • pronouns: he/him