1 Oct
2024
1 Oct
'24
3:20 p.m.
Taken to COFF...
Hi Arnold,
In main(), I *think* I'm assigning to the global
clientSet so that
I can use it later. But because of the 'err' and the :=, I've
actually created a local variable that shadows the global one, and in
otherfunc(), the global clientSet is still nil. Kaboom!
The correct way to write the code is:
var err error
clientSet, err = cluster.MakeClient() // or whatever
I think this is a common problem when learning Go, like assigning
getchar()'s value to a char in C. It was back in ’14 anyway, when I saw
https://www.qureet.com/blog/golang-beartrap/ which has an ‘err’ at an
outer scope be unwritten by the ‘:=’ with the new, assigned-to ‘err’
going un-checked.
The author mentions ‘go vet’ highlights these cases with -shadow, which
is off by default.
https://pkg.go.dev/github.com/golangci/govet#hdr-Shadowed_variables
suggests that's still the case.
--
Cheers, Ralph.