Golang包导入-找不到包

Question

This is my first time asking a question here, anyway, I am wondering why it says it can't find the package, even though github.com/JohnDoe/temperature/conversion/conv is inside the $GOPATH

[johndoe@johndoe temperature]$ go run main.go
main.go:5:2: cannot find package "github.com/JohnDoe/temperature/conversion/conv" in any of:
    /usr/local/go/src/github.com/JohnDoe/temperature/conversion/conv (from $GOROOT)
    /home/johndoe/Workspace/Go/src/github.com/JohnDoe/temperature/conversion/conv (from $GOPATH)

more details:

[johndoe@johndoe conversion]$ pwd
/home/johndoe/Workspace/Go/src/github.com/JohnDoe/temperature/conversion

[johndoe@johndoe conversion]$ ls
conv.go

Thoughts?