前进：找不到软件包“ fmt”错误

I'm trying to follow a simple Hello, World application in go:

package main

import (
    "fmt"
)

func main() {
    fmt.Println("Hello World!")
}

But when I build and run it, I get the following error:

main.go:5:2: cannot find package "fmt" in any of:
    /home/user/go/src/pkg/fmt (from $GOROOT)
    /home/user/gocode/src/fmt (from $GOPATH)
package test_program
    imports runtime: cannot find package "runtime" in any of:
    /home/user/go/src/pkg/runtime (from $GOROOT)
    /home/user/gocode/src/runtime (from $GOPATH)

Here is the ouput of go env:

GOARCH="amd64"
GOBIN=""
GOCHAR="6"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/user/gocode"
GORACE=""
GOROOT="/home/user/go"
GOTOOLDIR="/home/user/go/pkg/tool/linux_amd64"
CC="gcc"
GOGCCFLAGS="-g -O2 -fPIC -m64 -pthread"
CGO_ENABLED="1"

Unset GOROOT - the go tools know where they are supposed to be and you rarely need to set it.

You've set it to /home/user/go and unless you build go in there that is unlikely to be the right place to find the fmt package.

Don't use apt-get for installing go, just download the binaries and extract them to your home (or any) directory.

To get the go tool available in your terminal, you have to add the export PATH=$PATH:$GOROOT/bin line to your ~/.bashrc.