出现错误：“未使用fmt.Println”。 什么？

Question

What the title said. I'm getting an error:

fmt.Println not used

The line mentioned is the last line of my source file. I'm not using the fmt package in that file, but I did recently.

This happens when I try to build the package or run tests.

EDIT:

If I go clean myproject the project I still get the same response.

I ran just go clean and now have:

# myproject
<epoch>: fmt.Println not used

EDIT for the benefit of Cat Plus Plus, here's a source file triggering the error:

types2.go

package mypackage

import (
)

to run:

go build mypackage
# mypackage
./types2.go:4: fmt.Println not used

Yes you read that right.

Answer 1

The answer was that I had the expression fmt.Println in a file somewhere. The compiler told me that the error was occurring in incorrect file(s). More info in this blog post.

http://blog.afandian.com/2012/07/strange-error-in-go-fmt-println-not-used/