by kfox1111:

Before filing a bug, please check whether it has been fixed since the
latest release. Search the issue tracker and check that you're running the
latest version of Go:

Run "go version" and compare against
http://golang.org/doc/devel/release.html  If a newer version of Go exists,
install it and retry what you did to reproduce the problem.

Thanks.

What steps will reproduce the problem?
If possible, include a link to a program on play.golang.org.
1. on windows, create a file "test.txt". Right click on it and change its
permissions so that your user can't read it.

2.
foo, err = os.Open("test.txt")
if os.IsPermission(err) {
  fmt.Printf("Permission error!\n")

What is the expected output?
Permission error!

What do you see instead?
IsPermission does not return true

Which compiler are you using (5g, 6g, 8g, gccgo)?
6g

Which operating system are you using?
Windows

Which version are you using?  (run 'go version')
1

Please provide any additional information below.