ERROR: cannot discover where libxml2 is located on your system. please make sure `pkg-config` is installed.

nokogiri.sh

xcode-select --install
gem install nokogiri

¡does not recognize! other option, :)

C:\Ruby24-x64\code\test1>xcode-select --install
"xcode-select" no se reconoce como un comando interno o externo,
programa o archivo por lotes ejecutable.

ERROR: cannot discover where libxml2 is located on your system. please make sure
pkg-config is installed.
*** 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
--without-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=C:/Ruby24-x64/bin/$(RUBY_BASE_NAME)
--help
--clean
--use-system-libraries
--with-zlib-dir
--without-zlib-dir
--with-zlib-include
--without-zlib-include=${zlib-dir}/include
--with-zlib-lib
--without-zlib-lib=${zlib-dir}/lib
--with-xml2-dir
--without-xml2-dir
--with-xml2-include
--without-xml2-include=${xml2-dir}/include
--with-xml2-lib
--without-xml2-lib=${xml2-dir}/lib
--with-libxml-2.0-config
--without-libxml-2.0-config
--with-pkg-config
--without-pkg-config
--with-pkg-config
--without-pkg-config
--with-override-variables
--without-override-variables
--with-xslt-dir
--without-xslt-dir
--with-xslt-include
--without-xslt-include=${xslt-dir}/include
--with-xslt-lib
--without-xslt-lib=${xslt-dir}/lib
--with-libxslt-config
--without-libxslt-config
--with-exslt-dir
--without-exslt-dir
--with-exslt-include
--without-exslt-include=${exslt-dir}/include
--with-exslt-lib
--without-exslt-lib=${exslt-dir}/lib
--with-libexslt-config
--without-libexslt-config

To see why this extension failed to compile, please check the mkmf.log which can
be found here:

C:/Ruby24-x64/lib/ruby/gems/2.4.0/extensions/x64-mingw32/2.4.0/nokogiri-1.8.2/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in
C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/nokogiri-1.8.2 for inspection.
Results logged to
C:/Ruby24-x64/lib/ruby/gems/2.4.0/extensions/x64-mingw32/2.4.0/nokogiri-1.8.2/gem_make.out

An error occurred while installing nokogiri (1.8.2), and Bundler cannot
continue.
Make sure that gem install nokogiri -v '1.8.2' --source 'https://rubygems.org/' succeeds before bundling.

In Gemfile:
rails was resolved to 5.2.0, which depends on
actioncable was resolved to 5.2.0, which depends on
actionpack was resolved to 5.2.0, which depends on
actionview was resolved to 5.2.0, which depends on
rails-dom-testing was resolved to 2.0.3, which depends on
nokogiri

Is this for Linux?
I get xcode-select: command not found

No, this is for macOS

https://gist.github.com/sobstel/f6a490d854a2e5a214c3f2cd9c366032

Life saver, thanks a bunch