Failed to build gem native extension (mkmf (LoadError)) - Ubuntu 12.04
ruby, ruby-on-rails, ruby-on-rails-3, ubuntu-12.04
Solution
Possible duplicate of:
Unable to install gem - Failed to build gem native extension - cannot load such file -- mkmf (LoadError)
Depending on your ruby version, run:
sudo apt-get install ruby1.9.1-dev
Problem
Hey I'm trying to install rails on a new ubuntu machine. I have ruby and rvm installed but I'm getting a "failed to build gem native extension" error. What does this mean? ``` $ sudo gem install rails -v 3.2.9 ``` (without the sudo says I don't have permissions) Then it outputs a lot of 'fetching' commands and ultimately this error: ``` Building native extensions. This could take a while... ERROR: Error installing rails: ERROR: Failed to build gem native extension. /usr/bin/ruby1.9.1 extconf.rb /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- mkmf (LoadError) from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require' from extconf.rb:1:in `<main>' Gem files will remain installed in /var/lib/gems/1.9.1/gems/json-1.8.0 for inspection. Results logged to /var/lib/gems/1.9.1/gems/json-1.8.0/ext/json/ext/generator/gem_make.out ``` When I type ``` $rails server ``` It says rails is not currently installed