Merge pull request #199 from fhs/plan9

Fix build on Plan 9

Author: willscott

cli/error_plan9.go

@@ -0,0 +1,15 @@
+package cli
+
+import "syscall"
+
+func isErrnoNotSupported(err error) bool {
+	switch err {
+	case
+		// Operation not supported
+		syscall.EINVAL, syscall.EPLAN9,
+		// Sync on os.Stdin or os.Stderr returns "permission denied".
+		syscall.EPERM:
+		return true
+	}
+	return false
+}

cli/error_posix.go

@@ -1,4 +1,4 @@
-//+build !windows
+//+build !windows,!plan9
 
 package cli