Addresses @stevvooe's backward compatibility concerns.

logrus.go

@@ -121,7 +121,6 @@ type FieldLogger interface {
 	WithFields(fields Fields) *Entry
 	WithError(err error) *Entry
 
-	Tracef(format string, args ...interface{})
 	Debugf(format string, args ...interface{})
 	Infof(format string, args ...interface{})
 	Printf(format string, args ...interface{})
@@ -131,7 +130,6 @@ type FieldLogger interface {
 	Fatalf(format string, args ...interface{})
 	Panicf(format string, args ...interface{})
 
-	Trace(args ...interface{})
 	Debug(args ...interface{})
 	Info(args ...interface{})
 	Print(args ...interface{})
@@ -141,7 +139,6 @@ type FieldLogger interface {
 	Fatal(args ...interface{})
 	Panic(args ...interface{})
 
-	Traceln(args ...interface{})
 	Debugln(args ...interface{})
 	Infoln(args ...interface{})
 	Println(args ...interface{})
@@ -158,3 +155,12 @@ type FieldLogger interface {
 	// IsFatalEnabled() bool
 	// IsPanicEnabled() bool
 }
+
+// Ext1FieldLogger (the first extension to FieldLogger) is superfluous, it is
+// here for consistancy. Do not use. Use Logger or Entry instead.
+type Ext1FieldLogger interface {
+	FieldLogger
+	Tracef(format string, args ...interface{})
+	Trace(args ...interface{})
+	Traceln(args ...interface{})
+}

logrus_test.go

@@ -453,9 +453,12 @@ func TestReplaceHooks(t *testing.T) {
 }
 
 // Compile test
-func TestLogrusInterface(t *testing.T) {
+func TestLogrusInterfaces(t *testing.T) {
 	var buffer bytes.Buffer
-	fn := func(l FieldLogger) {
+	// This verifies FieldLogger and Ext1FieldLogger work as designed.
+	// Please don't use them. Use Logger and Entry directly.
+	fn := func(xl Ext1FieldLogger) {
+		var l FieldLogger = xl
 		b := l.WithField("key", "value")
 		b.Debug("Test")
 	}