fixing fixing“無法在go build

Understanding the Package Directory Structure

Go expects packages to reside in directories with the same name as their package names.導入軟件包時，“導入”語句指定軟件包名稱，而不是源文件名。因此，在您的示例中，應將foobar.go放在$ gopath/src/foobar/。

Place main.go in a subfolder under $GOPATH/src to better organize your projects.

Use "go install": Execute "go install test" (assuming your project is now in $GOPATH/src/test/) to install $ gopath/bin中的可執行文件，允許您直接從終端運行。