Recompiling again, and flushing the output of the compiler to a file to see whether I can track where that serialization bug comes from. Somehow, I hope it automagically disappears, but I am afraid it won't.
Odd bug. It lexes, parses, identifies, type checks, pretty prints, everything. But, suddenly, in the last minute, I have an operational error in the exact last module I wrote?
(I added yet an option more to the compiler to be able to unserialize and pretty print an AST. The bug persisted after the recompile. Going through the log to see in what stage it was introduced.)