Avoid uses `mruby/src/error.h` file
MODIFY
mrbgems/mruby-dir/mrbgem.rake
mrbgems/mruby-dir/mrbgem.rake
MRuby::Gem::Specification.new('mruby-dir') do |spec|
spec.license = 'MIT and MIT-like license'
spec.authors = [ 'Internet Initiative Japan Inc.', 'Kevlin Henney']
-
- spec.cc.include_paths << "#{build.root}/src"
end

MODIFY
mrbgems/mruby-dir/src/dir.c
mrbgems/mruby-dir/src/dir.c
#include "mruby.h"
#include "mruby/class.h"
#include "mruby/data.h"
+#include "mruby/error.h"
#include "mruby/string.h"
-#include "error.h"
#include <sys/types.h>
#if defined(_WIN32) || defined(_WIN64)
#define MAXPATHLEN 1024

Avoid uses `mruby/src/error.h` file