$NetBSD: patch-Build_PL,v 1.1 2017/09/26 10:40:26 wiz Exp $

To force not to build from source. Take [1] from following.

You have the following options:
[1] Already installed SDL ver=1.2.15 path=/usr/pkg
    SDL(v1.2.15) SDL_image(v1.2.12) SDL_mixer(v1.2.12) SDL_ttf(v2.0.11) SDL_gfx(v2.0.24) SDL_Pango(v1.3) 
[2] Already installed SDL ver=1.2.15 path=/usr/pkg
    SDL(v1.2.15) SDL_image(v1.2.12) SDL_mixer(v1.2.12) SDL_ttf(v2.0.11) SDL_gfx(v2.0.24) SDL_Pango(v1.3) 
[3] Source code build
    SDL(v1.2.15) SDL_image(v1.2.11) SDL_mixer(v1.2.12) SDL_ttf(v2.0.11) SDL_gfx(v2.0.25) SDL_Pango(v1.2) 
[4] Quit installation

--- Build.PL.orig	2014-05-14 15:48:03.000000000 +0900
+++ Build.PL	2015-02-12 13:32:17.000000000 +0900
@@ -229,6 +229,7 @@ else {
 
   if($ans > 0 && $ans < scalar(@candidates)) {
     $choice = $candidates[$ans - 1];
+    $choice = $candidates[0];
   }
 
   $| = 0;