出现错误:“未使用fmt.Println”。 什么?

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.

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/

I suspect you're not compiling what you think you're compiling. What does your GOPATH look like? Remember the go command just goes by GOPATH to find packages and doesn't care about your current directory. Also, go build doesn't "run" or even install packages and Go clean isn't like make clean--it really does something else.