Incorrect exception message for exceptions that inherit from Errno exceptions

[postmodern]

I noticed that TruffleRuby deviates from CRuby when an exception inherits from an Errno exception. The inherited Errno message (ex: No such file or directory) becomes lost.

Example

class CustomError < Errno::ENOENT
end

raise(CustomError,"custom message")

CRuby (3.0.2)

(irb):4:in `<main>': No such file or directory - custom message (CustomError)

TruffleRuby (21.3.0)

(irb):4:in `<top (required)>': unknown error - custom message (CustomError)

[eregon]

Thanks for the report.

@bjfish Could you look into this?
I think this condition is problematic: if error && error.class.equal?(self) and I guess we need to pass the self (the exception class) to SystemCallError.errno_error. The other usage of SystemCallError.errno_error doesn't know the correct class so we should probably split the logic to map errno->class to a separate Primitive.

[eregon]

Actually it might already work by changing error.class.equal?(self) to something like Primitive.object_kind_of?(error, self) since there is a super(*args) call which might deal fine with such cases.

[bjfish]

This is now fixed at 5776ef6.