Use Rake DSL instead of commands of `FileUtils`

- Respect `--verbose(-v)` and `--dry-run(-n)` options.
- Silence warnings to keyword arguments on Ruby 2.7.

1 files changed, 1 insertions, 1 deletions

diff --git a/mrbgems/mruby-bin-config/mrbgem.rake b/mrbgems/mruby-bin-config/mrbgem.rake
index 3a0a1b897..6005a876d 100644
--- a/mrbgems/mruby-bin-config/mrbgem.rake
+++ b/mrbgems/mruby-bin-config/mrbgem.rake
@@ -17,7 +17,7 @@ unless MRuby::Build.current.kind_of?(MRuby::CrossBuild)
       }]
       tmplt = File.read(tmplt_path)
       File.write(t.name, tmplt.gsub(/(#{Regexp.union(*config.keys)})\b/, config))
-      FileUtils.chmod(0755, t.name)
+      chmod(0755, t.name)
     end
   end
 end