Favicon return err

cmd/kjudge/main.go

@@ -54,7 +54,11 @@ func main() {
 
 	if *faviconfile != "" {
 		log.Printf("Serving favicon from %s", *faviconfile)
-		opts = append(opts, server.Favicon(*faviconfile))
+		opt, err := server.Favicon(*faviconfile)
+		if err != nil {
+			panic(err)
+		}
+		opts = append(opts, opt)
 	} else {
 		log.Printf("Not serving favicon")
 	}

server/opts.go

@@ -1,6 +1,10 @@
 package server
 
-import "os"
+import (
+	"os"
+
+	"github.com/pkg/errors"
+)
 
 // Opt represents an option for the server.
 type Opt func(s *Server)
@@ -13,11 +17,11 @@ func Verbose() Opt {
 }
 
 // Favicon makes the server serves given file at /favicon.ico
-func Favicon(path string) Opt {
+func Favicon(path string) (Opt, error) {
 	if _, err := os.Stat(path); err != nil {
-		panic(err)
+		return nil, errors.Wrap(err, "while searching for favicon")
 	}
 	return func(s *Server) {
 		s.faviconPath = path
-	}
+	}, nil
 }