Installing ZAT : ERROR: Error installing zendesk_apps_tools: ERROR: Failed to build gem native extension

Question

I'm following Installing and using the Zendesk apps tools documentation but I'm getting an error when trying to install ZAT.

Have searched some articles and followed all the step but still got the error.

ERROR:  Error installing zendesk_apps_tools:
        ERROR: Failed to build gem native extension.

    current directory: /var/lib/gems/2.5.0/gems/eventmachine-1.2.7/ext
/usr/bin/ruby2.5 -r ./siteconf20191007-7424-q18lo1.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/2.5.0/gems/eventmachine-1.2.7 for inspection.
Results logged to /var/lib/gems/2.5.0/extensions/x86_64-linux/2.5.0/eventmachine-1.2.7/gem_make.out

Answer 1

As Jimmy Long mentions in a comment:

The guide mentioned that ZAT doesn't work in Ruby 2.5 for Windows..

You'll need both ruby and gem to be at 2.6.5.