The mkmf-lite library is a light version of the the mkmf library designed for use as a library. It does not create packages, builds, or log files of any kind. Instead, it provides mixin methods that you can use in FFI or tests to check for the presence of header files, constants, and so on.
Gemfile gem 'mkmf-lite', '~> 0.2.0'
install gem install mkmf-lite -v 0.2.0