Some¹ of the Argument Clinic error messages only point to the problem in the clinic input, but do not suggest how to fix it. Suggesting to do an audit of clinic.py and improve the error messages that are too implicit or provide too little information/context to the developer.

Random selection of error messages that might be improved:

• "Too many var args" (how many are there now? what is too many?)
• "Not enough arguments for destination {name!r} new {type!r}" (how many arguments are expected, and what kind of arguments are they?)
• "Can't clear destination {name!r}: it's not of type 'buffer'" (what type is it?)
• "Custom printers are broken right now"
• "bool_converter: illegal 'accept' argument {accept!r}" (why is it illegal? how to fix this?)
• "char_converter: illegal default value {default!r}" (which values are legal? how to fix this?)
• "illegal combination of arguments""
• "'kind' of function and cloned function don't match! (@classmethod/@staticmethod/@coexist)" (what was the mismatch?)

(There might be better examples; this was the result of a very quick and short audit.)

cc. @sobolevn

Linked PRs

• gh-115077: Make some Argument Clinic error messages more helpful #115078
• gh-115077: Argument Clinic: generate better error messages when parsing function declaration #115555