"no declaration found" when a package uses a binary literal

[krisreeves-stripe]

This threw me for a loop because it was causing VS Code to fail to show context info on lots of stuff from a child package in a project I'm working on. I eventually narrowed it down to the following:

main.go

package main

import (
	"fmt"
	"godefbug/fails"
	"godefbug/works"
)

// Ping pongs
func Ping() string {
	bang := []byte{0b00100001}
	return fmt.Sprintf("Pong%s", bang)
}

func main() {
	fmt.Println(works.Ping())
	fmt.Println(fails.Ping())
	fmt.Println(Ping())
}

fails/fails.go

package fails

import "fmt"

// Ping pongs
func Ping() string {
	bang := []byte{0b00100001}
	return fmt.Sprintf("Pong%s", bang)
}

works/works.go

package works

import "fmt"

// Ping pongs
func Ping() string {
	bang := []byte{0x21}
	return fmt.Sprintf("Pong%s", bang)
}

output:

$ ~/go/bin/godef -t -f ./main.go -o 204
/Users/krisreeves/go/src/godefbug/works/works.go:6:6
Ping func() string
$ ~/go/bin/godef -t -f ./main.go -o 231
godef: no declaration found for &{fails Ping}
$ ~/go/bin/godef -t -f ./main.go -o 252
./main.go:10:6
Ping func() string
$ go run main.go
Pong!
Pong!
Pong!

It doesn't have to be looking at a function that is directly involved, either:

main.go

package main

import (
	"fmt"
	"godefbug/fails"
	"godefbug/works"
)

// Ping pongs
func Ping() string {
	bang := []byte{0b00100001}
	return fmt.Sprintf("Pong%s", bang)
}

func main() {
	fmt.Println(works.Ping())
	fmt.Println(fails.Ping())
	fmt.Println(Ping())
	fails.NotEvenTheSameFile()
}

fails/whatever.go:

package fails

import "fmt"

// NotEvenTheSameFile fails too
func NotEvenTheSameFile() {
	fmt.Println("???")
}

gives:

$ ~/go/bin/godef -t -f ./main.go -o 267
godef: no declaration found for &{fails NotEvenTheSameFile}