On building mruby with Rake, you may got "Too many open files" error. This is harmless. Please re-run ./minirake (or make).
This issue is reported by mruby/mruby#793.
Maybe dependencies are corrupt. type ./minirake clean. Or git clean -xdf also effective.
./minirake clean
git clean -xdf
There was an error while loading. Please reload this page.