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I don't understand why any of these should produce an error/warning. Could you please point me to the section(s) in the specification where they are defined?

Set owner to @peter-ahe-google.
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I guess the specification is unclear about these situations leading to warnings. I've filed issue #21521.

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Marked this as being blocked by #21521.

The part of the spec mentioning "main" is the Script section.
The current LaTeX version in the repository requires:

• A runtime error if the library doesn't have a declared or imported top-level function called "main".
• A static warning if "main" has more than two required parameters.
• and, implied by the way it's called, a runtime error if "main" requires more than two parameters (it's called with zero, one or two positional parameters, depending on how many it allows, and if it requires more than two, it's still called with two, causing the error).

The requirement that "main" is a top-level function disallows things like:
  var main = () { print("Hello world!"); }
  var main = new CallableObject();
  var main = new ObjectWithNoSuchMethod();
which could otherwise have allowed "main(arg1, arg2)" to succeed.

(The VM allows all three examples).

"- and, implied by the way it's called, a runtime error if "main" requires
more than two parameters (it's called with zero, one or two positional
parameters, depending on how many it allows, and if it requires more than
two, it's still called with two, causing the error)."

I'm not sure how to reach that conclusion from the actual text in the specification.

The part of the spec mentioning "main" is the Script section.

Correct. But what distinguishes a script from a library? In other words, how should the analyzer decide that a file is a script as well as a library and that this requirement therefore applies?

Unless someone wants to continue the discussion, I'm closing this issue.

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