CLI fails silently on v4.30.0+ when using module system

[joneugster]

Up to v4.29.1, it was possible to use the module system for the entry point of an executabl (Main.lean in the template lake projects). In v4.30.0 this will cause lean4-cli to fail silently resulting in a no-op when the executable is called.

Reproduction

I've created an MWE-repo with 2 commits, one working in v4.29.1 and one failing in v4.30.0:

https://github.com/joneugster/lean-cli-bug-demo/commits/main/

The key is that Main.lean contains

module

...

public meta def main (args : List String) : IO UInt32 :=
  i18n.validate args

If module is removed from Main.lean turning it into a plain Lean file, it works again.