build_config.patch

diff --git i/build_config.rb w/build_config.rb
index 7f52b5ee..c20be4c0 100644
--- i/build_config.rb
+++ w/build_config.rb
@@ -22,6 +22,9 @@ MRuby::Build.new do |conf|
   # conf.gem :github => 'iij/mruby-io'
   # conf.gem :git => '[email protected]:iij/mruby-io.git', :branch => 'master', :options => '-v'
 
+  conf.gem :github => 'iij/mruby-env'
+  conf.gem :github => 'mattn/mruby-curl'
+  conf.gem :github => 'k0kubun/mruby-yaml'
   # include the default GEMs
   conf.gembox 'default'
   # C compiler settings