Why isn't Nokogiri installing?

问题

I'm having trouble installing Nokogiri. When I run bundle install or gem install nokogiri the installation fails.

The error I'm getting is: (Note: This failure is from using the installation command on nokogiri.org)

Building native extensions.  This could take a while...
ERROR:  Error installing nokogiri:
    ERROR: Failed to build gem native extension.

    /Users/roneesh/.rbenv/versions/1.9.3-p194/bin/ruby extconf.rb --with-xml2-include=/usr/local/Cellar/libxml2/2.9.1/include/libxml2 --with-xml2-lib=/usr/local/Cellar/libxml2/2.9.1/lib --with-xslt-dir=/usr/local/Cellar/libxslt/1.1.28/ --with-iconv-include=/usr/local/Cellar/libiconv/1.14/include --with-iconv-lib=/usr/local/Cellar/libiconv/1.14/lib
Extracting libxml2-2.8.0.tar.gz into tmp//ports/libxml2/2.8.0... OK
Running 'configure' for libxml2 2.8.0... ERROR, review 'tmp//ports/libxml2/2.8.0/configure.log' to see what happened.
*** 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.

The command I'm trying to use is:

gem install nokogiri -- --with-xml2-include=/usr/local/Cellar/libxml2/2.9.1/include/libxml2 --with-xml2-lib=/usr/local/Cellar/libxml2/2.9.1/lib --with-xslt-dir=/usr/local/Cellar/libxslt/1.1.28/ --with-iconv-include=/usr/local/Cellar/libiconv/1.14/include --with-iconv-lib=/usr/local/Cellar/libiconv/1.14/lib

I have installed xml2, xslt and libiconv all with brew, and put in their proper versions above. Still no resolution. The only thing I haven't done is libiconv from source (my wget command isn't working for some reason).

回答1:

You need to specify nokogiri to use the system libraries instead, so it doesn't try to build them itself.

NOKOGIRI_USE_SYSTEM_LIBRARIES=1 bundle install

Answer found here: Error installing nokogiri 1.6.0 on mac (libxml2).

回答2:

Setting NOKOGIRI_USE_SYSTEM_LIBRARIES=1 also did the trick for me, but I had to install the native libraries the gem depends on first (I did it with Homebrew) and then tell the gem to use them.

Summarising:

• If previously installed, uninstall the gem:
  $ gem uninstall nokogiri

• Use Homebrew to install libxml2, libxslt and libiconv:
  $ brew install libxml2 libxslt libiconv

• Install the gem specifying the paths to the libraries to be linked against:
  $ NOKOGIRI_USE_SYSTEM_LIBRARIES=1 gem install nokogiri -- --use-system-libraries --with-iconv-dir="$(brew --prefix libiconv)" --with-xml2-config="$(brew --prefix libxml2)/bin/xml2-config" --with-xslt-config="$(brew --prefix libxslt)/bin/xslt-config"

来源：https://stackoverflow.com/questions/17914169/why-isnt-nokogiri-installing