How do I make go find my package?

Question

Where should I put my package so that it can be imported by another package?

$ tree
.
├── main.go
└── src
    └── test.go

1 directory, 2 files

$ cat src/test.go 
package test

$ cat main.go 
package main

import "test"

$ go build main.go 
main.go:3:8: import "test": cannot find package

Answer 1

There are a few things that need to happen. You must install the "test" package first:

$ export GOPATH=$(pwd)   # Assumes a bourne shell (not csh)
$ mkdir src/test
$ mv src/test.go src/test/test.go
$ mkdir pkg                 # go install will put packages here
$ go install test           # build the package and put it in $GOPATH/pkg
$ go build main.go

Note that it is not necessary to create pkg, as go install will do that for you. Once you've installed the test package (generally a bad name, BTW) go build main.go should now give different errors (eg, "imported and not used")

Answer 2

Set your GOPATH. Put your package foo source(s) in GOPATH/src/optional-whatever/foo/*.go and use it in code as

import "optional-whatever/foo"

You don't need to explicitly install foo, the go tool is a build tool, it will do that automagically for you whenever necessary.

Answer 3

也许，你可以将test.go文件放在与main.go相同的目录中，在test.go中，它使用如下内容：

import "./test"