runtime: wrong Unix error code from panic.

[robpike]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version devel +baf3eb1625 Tue Mar 6 01:11:26 2018 +0000 darwin/amd64

% cat p.go
package main

func main() {
	panic(3)
}
% ./p
panic: 3

goroutine 1 [running]:
main.main()
	/Users/r/p.go:4 +0x39
% echo $?
2
% 

Exit code 2 traditionally means 'incorrect arguments', as in flag.Usage.

Panic should be something like 127 or 255 on Unix.

Reported by darren.e.grant@gmail.com on nuts.

[LDMFD]

or simply 1 meaning 'general error' ?

(http://tldp.org/LDP/abs/html/exitcodes.html)

[robpike]

As has been pointed out in the mail thread, it might be best to leave this alone and say that the error that triggered this is in a program that takes exit code 2 as 'success'. That is certainly nonstandard.

[LDMFD]

Sure, although a note in the language spec might avoid some similar confusion in the future..

I'll open an issue with Supervisor (http://supervisord.org/)

[andybons]

/cc @aclements

[ianlancetaylor]

E-mail thread is at https://groups.google.com/d/msg/golang-nuts/u9NgKibJsKI/XxCdDihFDAAJ .

[LDMFD]

Thanks!

[odeke-em]

How's it going @cachvico? Any news from filing the bug with Supervisord?

@ianlancetaylor sure let's document in the spec that a panic returns a non-zero code to the shell.
@robpike @aclements shall we proceed with making a panic return 127 or 255? @robpike if you might have time, a reference to a UNIX manual would be useful for us to include in the commit for posterity.