Error when installing rails, failed to build gem native extension - ruby-on-rails

Question

I'm following this Go Rails tutorial and I'm running into trouble when I reach the step to install rails. I'm calling
sudo gem install rails -v 5.0.1
in the terminal and getting this error:
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
current directory: /usr/local/lib/ruby/gems/2.4.0/gems/nokogiri-1.7.0.1/ext/nokogiri
/usr/local/opt/ruby/bin/ruby -r ./siteconf20170302-50105-1af2foa.rb extconf.rb
checking if the C compiler accepts ... yes
checking if the C compiler accepts -Wno-error=unused-command-line-argument-hard-error-in-future... no
Building nokogiri using packaged libraries.
Using mini_portile version 2.1.0
checking for iconv.h... yes
checking for gzdopen() in -lz... no
zlib is missing; necessary for building libxml2
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/local/Cellar/ruby/2.4.0/bin/$(RUBY_BASE_NAME)
--help
--clean
--use-system-libraries
--enable-static
--disable-static
--with-zlib-dir
--without-zlib-dir
--with-zlib-include
--without-zlib-include=${zlib-dir}/include
--with-zlib-lib
--without-zlib-lib=${zlib-dir}/lib
--enable-cross-build
--disable-cross-build
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/usr/local/lib/ruby/gems/2.4.0/extensions/x86_64-darwin-16/2.4.0/nokogiri-1.7.0.1/mkmf.log
extconf failed, exit code 1
Gem files will remain installed in /usr/local/lib/ruby/gems/2.4.0/gems/nokogiri-1.7.0.1 for inspection.
Results logged to /usr/local/lib/ruby/gems/2.4.0/extensions/x86_64-darwin-16/2.4.0/nokogiri-1.7.0.1/gem_make.out
I'm not really sure what to make of this. I've tried reinstalling uninstalling and reinstalling zlib but it didn't seem to change anything. I'm on OS X Sierra version 10.12.3 by the way.

Answer 1

Solved by this thread using
sudo gem install rails -- --use-system-libraries --with-xml=/usr/local/Cellar/libxml2/