Posting this here since it was recommended that I do so since the bug tracker is no longer up.
When trying to compile
After reading a command: if the player's command matches string of Debug: say "something".
where Debug is either a thing or an instance of a kind of thing, and string is a text (or an indexed text), the following error is thrown:
>--> An internal error has occurred: Parse tree broken. The error was detected at line 1656 of "inform7/Chapter 13/Parse Tree.w". This should never happen, and I am now halting in abject failure.
This bug does not occur with
if the player's command matches string:, only when it’s specified what object the text is a part of.
This bug can be replicated in a new project with no extensions.