The following two errors occurred:

zlib is missing; necessary for building libxml2

xslt is missing. Please locate mkmf.log to investigate how it is failing.

Solution

• Install libxslt and libxml2
• Specify the path of libxml2 installed by brew

brew install libxslt libxml2
bundle config build.nokogiri --use-system-libraries --with-xml2-include=$(brew --prefix libxml2)/include/libxml2

Reference sites

• Don't hate nokogiri Overcoming installation errors
• nokogiri cannot be installed on macOS