i'm noob. This is my problem when i try.

Building native extensions. This could take a while... ERROR: Error installing rails: ERROR: Failed to build gem native extension.

current directory: /var/lib/gems/2.3.0/gems/nio4r-1.2.1/ext/nio4r

/usr/bin/ruby2.3 -r ./siteconf20160630-19108-12sbtb7.rb extconf.rb mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /var/lib/gems/2.3.0/gems/nio4r-1.2.1 for inspection. Results logged to /var/lib/gems/2.3.0/extensions/x86-linux/2.3.0/nio4r-1.2.1/gem_make.out

  • What commands did you use to try to install Rails?
    – edwinksl
    Jul 1, 2016 at 1:31

1 Answer 1


I needed to install ruby-dev:

sudo apt-get install ruby-dev zlib1g-dev liblzma-dev

Cf: This question on StackOverflow. It recommends sudo apt-get install build-essential patch first, but my system didn't need that.

  • Simply sudo apt install ruby-dev did it for me on 17.10 Sep 30, 2017 at 13:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.