This tripped me up for a little while, so I thought I’d post it in the hope that it will save someone else some head-scratching.
If you’re running Ruby on Windows and trying to install a gem that uses native extensions, you may get an error like this (depending on how you got Ruby on to your machine):
$ gem install jekyll Building native extensions. This could take a while... ERROR: Error installing jekyll: ERROR: Failed to build gem native extension. c:/Ruby191/bin/ruby.exe extconf.rb creating Makefile make 'make' is not recognized as an internal or external command, operable program or batch file.
Turns out the answer is quite simple: RubyInstaller DevKit.
The site has the full instructions, but to give you a quick summary it is just a matter of downloading DevKit, extracting it somewhere, then running
ruby dk.rb init followed by
ruby dk.rb install. I was very impressed with how easy it was to get working.
Hope this helps.