playground: vet and compile disagree on size of int

[vcabbage]

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

I can only reproduce in the Go Playground

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

What did you do?

package main

import (
	"unsafe"
)

type myStruct struct {
	a, b int
}

var _ [8]byte = [unsafe.Sizeof(myStruct{})]byte{}

func main() {}

https://play.golang.org/p/asSsu2foRHF

What did you expect to see?

Successful compile.

What did you see instead?

prog.go:11:5: cannot use [16]byte literal (type [16]byte) as type [8]byte in assignment

Attempting to change the declaration to [16]byte results in:

prog.go:11:5: cannot use [8]byte literal (type [8]byte) as type [16]byte in assignment

This doesn't reproduce when compiling for amd64 or 386, so I expect it's specific to nacl.

[ianlancetaylor]

This is a playground specific problem. One error is coming from vet. One is coming from the compiler. The problem is that vet and the compiler when run on the playground don't agree on the size of int. You can see this more clearly if you change the main function to actually print something. In the case with the vet error, you will see the error, and you will also see the output.

[vcabbage]

I completely missed that the message was from vet. Thanks!

[agnivade]

/cc @ysmolsky

[bcmills]

Duplicate of #27885.