Trying to reproduce data race in Golang 1.8.3

I try to reproduce race condition in my app, but go build -race doesnt show any error, even on virtual machine with Linux onboard.

Machine:
Windows: 4 cores
Linux: 2 cores (Ubuntu Xenial x64 via Vagrant and VirtualBox)

go version:
Linux: go version go1.8.3 linux/amd64
Windows: go version go1.8.3 windows/amd64

go env:
Linux: https://pastebin.com/pXURKfj3
Windows: https://pastebin.com/MTdjNnVW

Example 1: https://play.golang.org/p/x-eD6bBrzz
Example 2: https://play.golang.org/p/FSg8P7UP8p

Is my examples has data race? Both of them no according to build with go build -race

If examples above hasnt data race condition, could somebody please send me example where i can see a real data race in Golang, so i can test the -race flag? I also found some examples on the web, some of them doesnt compiling, some of them same shows that there is no data race.

Thank you!

Both of your examples has data race issue. You can find out data race in following ways.

1. go run -race program.go
2. go test -race <package-name> or go test -race -run=<testcase-func-name>
3. go build -race program.go then execute the program
4. go install -race <package-name> then execute the program

Example 1: data race info

$ go build -race datarace-try1.go
$ ./datarace-try1
8
==================
WARNING: DATA RACE
Read at 0x00c4200761a8 by goroutine 7:
  main.main.func1()
      /Users/jeeva/go_playground/datarace-try1.go:23 +0x74

Previous write at 0x00c4200761a8 by goroutine 6:
  main.main.func1()
      /Users/jeeva/go_playground/datarace-try1.go:23 +0x8d

Goroutine 7 (running) created at:
  main.main()
      /Users/jeeva/go_playground/datarace-try1.go:25 +0xee

Goroutine 6 (running) created at:
  main.main()
      /Users/jeeva/go_playground/datarace-try1.go:25 +0xee
==================
187410
Found 1 data race(s)

Example 2: data race info

$ go build -race datarace-try2.go
$ ./datarace-try2
==================
WARNING: DATA RACE
Read at 0x00c420078178 by main goroutine:
  main.main()
      /Users/jeeva/go_playground/datarace-try2.go:10 +0x12e

Previous write at 0x00c420078178 by goroutine 6:
  main.main.func1()
      /Users/jeeva/go_playground/datarace-try2.go:15 +0xd4

Goroutine 6 (finished) created at:
  main.main()
      /Users/jeeva/go_playground/datarace-try2.go:17 +0xf1
==================
==================
WARNING: DATA RACE
Read at 0x00c420078178 by goroutine 7:
  main.main.func2()
      /Users/jeeva/go_playground/datarace-try2.go:20 +0x3f

Previous write at 0x00c420078178 by goroutine 6:
  main.main.func1()
      /Users/jeeva/go_playground/datarace-try2.go:15 +0xd4

Goroutine 7 (running) created at:
  main.main()
      /Users/jeeva/go_playground/datarace-try2.go:23 +0x11d

Goroutine 6 (finished) created at:
  main.main()
      /Users/jeeva/go_playground/datarace-try2.go:17 +0xf1
==================
finish
Found 2 data race(s)
exit status 66