Could not find nokogiri-1.8.1 in any of the sources (Bundler::GemNotFound)

[dannysiu392005]

(I was at branch my-07-requests)When I tried to run rspec, I had the following error:
Could not find nokogiri-1.8.1 in any of the sources (Bundler::GemNotFound). And finally, I found a solution to install nokogiri-1.8.1 by this commandgem install nokogiri -v '1.8.1' -- --use-system-libraries --with-xslt-dir=/usr/local/opt/libxslt --with-xml2-include=/usr/local/opt/libxml2/include/libxml2 --with-xml2-lib=/usr/local/opt/libxml2/lib

[ruralocity]

Nokogiri should have been installed as part of chapter 6's changes. Did you run the bundle command in that chapter?

[dannysiu392005]

When I ran bundle, I have the following error messages:

Warning: the running version of Bundler (1.14.2) is older than the version that created the lockfile (1.14.6). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
Fetching gem metadata from https://rubygems.org/...........
Fetching version metadata from https://rubygems.org/...
Fetching dependency metadata from https://rubygems.org/..
Using rake 12.0.0
Using concurrent-ruby 1.0.5
Using i18n 0.8.1
Using minitest 5.10.2
Using thread_safe 0.3.6
Using builder 3.2.3
Using erubi 1.6.0
Using mini_portile2 2.3.0
Using rack 2.0.3
Using nio4r 2.0.0
Using websocket-extensions 0.1.2
Using mime-types-data 3.2016.0521
Using arel 8.0.0
Using public_suffix 3.0.0
Using io-like 0.3.0
Using execjs 2.7.0
Using bcrypt 3.1.11
Using bindex 0.5.0
Using sass 3.4.23
Using byebug 9.0.6
Using mini_mime 0.1.4
Using ffi 1.9.18
Using climate_control 0.2.0
Using coffee-script-source 1.12.2
Using method_source 0.8.2
Using thor 0.19.4
Using orm_adapter 0.5.0
Using diff-lcs 1.3
Using geocoder 1.4.4
Using multi_json 1.12.1
Using rb-fsevent 0.9.8
Using ruby_dep 1.5.0
Using mimemagic 0.3.2
Using puma 3.8.2
Using bundler 1.14.2
Using rspec-support 3.6.0
Using rubyzip 1.2.1
Using tilt 2.0.7
Using sqlite3 1.3.13
Using turbolinks-source 5.0.0
Using faker 1.7.3
Using tzinfo 1.2.3
Installing nokogiri 1.8.1 with native extensions
Using rack-test 0.6.3
Using warden 1.2.7
Using sprockets 3.7.1
Using websocket-driver 0.6.5
Using mime-types 3.1
Using addressable 2.5.2
Using archive-zip 0.11.0
Using autoprefixer-rails 6.7.7.2
Using uglifier 3.2.0
Using childprocess 0.8.0
Using rb-inotify 0.9.8
Using cocaine 0.5.8
Using coffee-script 2.4.1
Using rspec-core 3.6.0
Using rspec-expectations 3.6.0
Using rspec-mocks 3.6.0
Using turbolinks 5.0.1
Using activesupport 5.1.1
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/dannysiu392005/.rvm/gems/ruby-2.3.3/gems/nokogiri-1.8.1/ext/nokogiri
/Users/dannysiu392005/.rvm/rubies/ruby-2.3.3/bin/ruby -r ./siteconf20180816-2398-ylgjpp.rb extconf.rb --use-system-libraries
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 system libraries.
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
	--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=/Users/dannysiu392005/.rvm/rubies/ruby-2.3.3/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=${xml2-dir}/lib
	--with-libxml-2.0-config
	--without-libxml-2.0-config
	--with-pkg-config
	--without-pkg-config
	--with-xslt-dir
	--without-xslt-dir
	--with-xslt-include
	--without-xslt-include=${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:

  /Users/dannysiu392005/.rvm/gems/ruby-2.3.3/extensions/x86_64-darwin-16/2.3.0/nokogiri-1.8.1/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in /Users/dannysiu392005/.rvm/gems/ruby-2.3.3/gems/nokogiri-1.8.1 for inspection.
Results logged to /Users/dannysiu392005/.rvm/gems/ruby-2.3.3/extensions/x86_64-darwin-16/2.3.0/nokogiri-1.8.1/gem_make.out

An error occurred while installing nokogiri (1.8.1), and Bundler cannot continue.
Make sure that `gem install nokogiri -v '1.8.1'` succeeds before bundling.

[ruralocity]

Can you tell me more about your environment? Operating system and version, in particular. Nokogiri can be notoriously difficult to install on some systems.

[dannysiu392005]

I'm using macOS High Sierra Version 10.13.6