Include calling filename and line # in error logs

...instead of the filename and line number of the Printf call in
log.Error()

log/log.go

@@ -2,8 +2,10 @@
 package log
 
 import (
+	"fmt"
 	"log"
 	"os"
+	"runtime"
 )
 
 var (
@@ -13,7 +15,7 @@ var (
 
 func init() {
 	InfoLog = log.New(os.Stdout, "", log.Ldate|log.Ltime)
-	ErrorLog = log.New(os.Stderr, "ERROR: ", log.Ldate|log.Ltime|log.Lshortfile)
+	ErrorLog = log.New(os.Stderr, "ERROR: ", log.Ldate|log.Ltime)
 }
 
 // Info logs an informational message to Stdout.
@@ -23,5 +25,18 @@ func Info(s string, v ...interface{}) {
 
 // Error logs an error to Stderr.
 func Error(s string, v ...interface{}) {
-	ErrorLog.Printf(s, v...)
+	// Include original caller information
+	_, file, line, _ := runtime.Caller(1)
+
+	// Determine short filename (from standard log package)
+	short := file
+	for i := len(file) - 1; i > 0; i-- {
+		if file[i] == '/' {
+			short = file[i+1:]
+			break
+		}
+	}
+	file = short
+
+	ErrorLog.Printf(fmt.Sprintf("%s:%d: ", short, line)+s, v...)
 }