Nokogiri says versions of Libxml2 above 2.9.0 are broken, is it?

Question

The message on installation says so, but I can't find any reference to it. "are currently known to be broken", but known by whom, and what is the problem? I've checked the Nokogiri code base and issue log, but I can't find the reference to this.

Here's the (relevant parts of the) message Nokogiri (v1.6.3.1 in this case) gives:

IMPORTANT!  Nokogiri builds and uses a packaged version of libxml2.

If this is a concern for you and you want to use the system library
instead, abort this installation process and reinstall nokogiri as
follows:

    gem install nokogiri -- --use-system-libraries

If you are using Bundler, tell it to use the option:

    bundle config build.nokogiri --use-system-libraries
    bundle install

However, note that nokogiri does not necessarily support all versions
of libxml2.

For example, libxml2-2.9.0 and higher are currently known to be broken
and thus unsupported by nokogiri, due to compatibility problems and
XPath optimization bugs.

Answer 1

There might be two ways: 1. use system libraries as it indicate:

gem install nokogiri -- --use-system-libraries 

2. it might be grep problem, indicated here, and you might be able to get over it by a shell command (assuming using Bash):

export GREP_OPTIONS="--color=auto"