Go无法检测到`sync`软件包

Question

I get error: reference to undefined identifier ‘sync.Pool’ message and this is working in Playground. What should I do?

package main

import (
  "fmt"
  "sync"
)

func main() {
  var wg sync.Pool
  fmt.Println(wg)
}

Answer 1

If you installed go from source, check what $GOROOT et ^$GOROOT_FINAL refer to: if they differ, you need to reset your GOROOT to GOROOT_FINAL.

The value assumed by installed binaries and scripts when $GOROOT is not set explicitly.
It defaults to the value of $GOROOT.

If you want to build the Go tree in one location but move it elsewhere after the build, set $GOROOT_FINAL to the eventual location.

---

From the comments, the OP mentions:

go version prints out

go version xgcc (Ubuntu 4.9.1-0ubuntu1) 4.9.1 linux/amd64 

And $GOROOT/pkg/linux_amd64/sync.a does exist.

I recommended to make sure $PATH includes $GOROOT/bin JimB added:

to be more specific, make sure your $PATH contains $GOROOT/bin for the correct GOROOT. I think you have two installations making this more confusing.