# FFI gem build failure on Ruby 3.x

**URL:** <https://discuss.rubyonrails.org/t/ffi-gem-build-failure-on-ruby-3-x/79727>\
**Category:** rubyonrails-talk\
**Tags:** ruby-language\
**Created:** [January 8, 2022, 12:12pm UTC](https://discuss.rubyonrails.org/t/ffi-gem-build-failure-on-ruby-3-x/79727 "2022-01-08T12:12:39Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Brian\_Piercy](https://sea2.discourse-cdn.com/rubyonrails/user_avatar/discuss.rubyonrails.org/brian_piercy/32/4576_2.png) [@Brian\_Piercy](https://discuss.rubyonrails.org/u/Brian_Piercy)\
**Post date:** [January 8, 2022, 12:12pm UTC](https://discuss.rubyonrails.org/t/ffi-gem-build-failure-on-ruby-3-x/79727/1 "2022-01-08T12:12:39Z")

</div>

Hi everyone, Tried creating a sandbox app using Ruby 3.0.2 with RoR 6.1.4 & 7.0.1. The build crashes in both cases due to an FFI gem native build failure on extconf.rb.

Error msg: “/home/bjpcjp/.rbenv/versions/3.0.2/lib/ruby/3.0.0/mkmf.rb:471:in `try\_do’: The compiler failed to generate an executable file. (RuntimeError) - You have to install development tools first.”

I didn’t notice any further help verbage, and don’t know what tools are missing.

I’ve tried uninstalling & reinstalling the gem. No success.