Install ruby headers for gitlab

Hi! I’m trying to install tiny_tds and getting the following error, as far as I understand I need to install ruby headers for gitlab, but how to do that?

sudo /opt/gitlab/embedded/bin/gem install tiny_tds

and got an error:
Building native extensions. This could take a while…
ERROR: Error installing tiny_tds:
ERROR: Failed to build gem native extension.

current directory: /opt/gitlab/embedded/lib/ruby/gems/2.4.0/gems/tiny_tds-2.1.2/ext/tiny_tds
/opt/gitlab/embedded/bin/ruby -r ./siteconf20180626-7667-io4mzv.rb extconf.rb
mkmf.rb can’t find header files for ruby at /opt/gitlab/embedded/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /opt/gitlab/embedded/lib/ruby/gems/2.4.0/gems/tiny_tds-2.1.2 for inspection.
Results logged to /opt/gitlab/embedded/lib/ruby/gems/2.4.0/extensions/x86_64-linux/2.4.0/tiny_tds-2.1.2/gem_make.out

What should I do to make it work?