Merge pull request ethereum#3043 from fjl/windows-fix-fatalf

cmd/utils: don't check for stderr redirect on windows

cmd/utils/cmd.go

@@ -23,6 +23,7 @@ import (
 	"os"
 	"os/signal"
 	"regexp"
+	"runtime"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
@@ -52,10 +53,16 @@ func openLogFile(Datadir string, filename string) *os.File {
 // is redirected to a different file.
 func Fatalf(format string, args ...interface{}) {
 	w := io.MultiWriter(os.Stdout, os.Stderr)
-	outf, _ := os.Stdout.Stat()
-	errf, _ := os.Stderr.Stat()
-	if outf != nil && errf != nil && os.SameFile(outf, errf) {
-		w = os.Stderr
+	if runtime.GOOS == "windows" {
+		// The SameFile check below doesn't work on Windows.
+		// stdout is unlikely to get redirected though, so just print there.
+		w = os.Stdout
+	} else {
+		outf, _ := os.Stdout.Stat()
+		errf, _ := os.Stderr.Stat()
+		if outf != nil && errf != nil && os.SameFile(outf, errf) {
+			w = os.Stderr
+		}
 	}
 	fmt.Fprintf(w, "Fatal: "+format+"\n", args...)
 	logger.Flush()