맥북에서 nokogiri gem install 오류 해결

맥북에서 nokogiri gem install 시에 libxml2 경로를 찾지 못하는 문제 발생함.

Solution

in Rails 6

gem install nokogiri -- --use-system-libraries=true --with-xml2-include="$(xcrun --show-sdk-path)"/usr/include/libxml2

in Rails 5

bundle config build.nokogiri --use-system-libraries --with-xml2-include=/usr/local/opt/libxml2/include/libxml2

Error Log

Installing nokogiri 1.10.7 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /Users/andrew/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/nokogiri-1.10.7/ext/nokogiri
/Users/andrew/.rbenv/versions/2.6.0/bin/ruby -I /Users/andrew/.rbenv/versions/2.6.0/lib/ruby/2.6.0 -r
./siteconf20200204-2474-1u695rc.rb extconf.rb --use-system-libraries\=true\
--with-xml2-include\=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/libxml2
checking if the C compiler accepts  -I /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/libxml2... 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: