NotImplementedError when placing a substituion in a todo.
When I place a substitution in a todo item, I get a NotImplementedError.
Comment on how much I like to use |appname|.
Raises this error, with this added to the log:
NotImplementedError: visiting unimplemented node type: substitution_reference }}}
When this oocurs, it is often not immediately clear where the error is in the source file.
Implement the substitution in the todo extension
Point out where the error is in the make output