==================
WARNING: DATA RACE
Write by goroutine 139:
  main.func·001()
      /home/szamcsi/w/go/lc/v4.go:50 +0x15b

Previous write by goroutine 144:
  main.func·001()
      /home/szamcsi/w/go/lc/v4.go:50 +0x15b

Goroutine 139 (running) created at:
  main.visit()
      /home/szamcsi/w/go/lc/v4.go:53 +0x120
  path/filepath.walk()
      /usr/local/go/src/pkg/path/filepath/path.go:341 +0x82
  path/filepath.walk()
      /usr/local/go/src/pkg/path/filepath/path.go:359 +0x3e9
  path/filepath.Walk()
      /usr/local/go/src/pkg/path/filepath/path.go:380 +0xc9
  main.main()
      /home/szamcsi/w/go/lc/v4.go:60 +0x65

Goroutine 144 (finished) created at:
  main.visit()
      /home/szamcsi/w/go/lc/v4.go:53 +0x120
  path/filepath.walk()
      /usr/local/go/src/pkg/path/filepath/path.go:341 +0x82
  path/filepath.walk()
      /usr/local/go/src/pkg/path/filepath/path.go:359 +0x3e9
  path/filepath.Walk()
      /usr/local/go/src/pkg/path/filepath/path.go:380 +0xc9
  main.main()
      /home/szamcsi/w/go/lc/v4.go:60 +0x65
==================
Found 1 data race(s)