Question

I installed a test0 package to $gopath\pkg\windows_386\hello\test0.a, but when i build a main package which depends on the test0 package, the compiler says: import "hello/test0": cannot find package.

why this happens?

I have two go file:

$gopath/src/hello.go

package main

import (
    "fmt"
    "hello/test0"
)

func main() {
    fmt.Println(test0.Number)
}

$gopath/src/hello/test0/test0.go

package test0

const (
    Number int = 255
)

At first, i run go install hello/test0, and it generated $gopath\pkg\windows_386\hello\test0.a

then, i delete the directory $gopath/src/hello

finally, i run go build hello.go, and the compiler sayed hello.go:5:2: import "hello/test0": cannot find package

Answer 1

That doesn’t seem to be normally possible for the moment : https://code.google.com/p/go/issues/detail?id=2775

Maybe for Go1.1

A trick (that I didn’t test) by Dave :

For a package called “hello”, the go tool will look for .go sources in
$GOPATH/src/hello, and only rebuild if the timestamp of the .a file is
before the latest timestamp of the .go files. An easy way to fool it
into accepting just the .a file is to drop a dummy .go file in the
correct src directory and set its timestamp to before that of the .a
file.

(this is a community answer, using what is said on golang-nuts).