> 20+ years of Python success suggest this isn't a problem that needs solving.

That reasoning could be applied to almost all open tracker issues.

> Likewise, Linux itself doesn't preserve the original form of a chmod call.

Where would/could it do so?  C has no introspection facility equivalent to pydoc, which is discussed here.  In the Linux manual pages, octal literals are used.  Introspective tools like "strace" also display octal literals when tracing *chmod calls.

That said, I agree that this is not an issue worth solving just because of octal literals.  But there are more cases in which the actual signature doesn't represent the best way to document the function API, and if a simple solution can be found it would not be different from fixing a minor annoyance elsewhere in Python.