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

/usr/bin/ruby extconf.rb install mechanize
checking for xmlParseDoc() in -lxml2... no
checking for xsltParseStylesheetDoc() in -lxslt... no
checking for exsltFuncRegister() in -lexslt... no
checking for #include <libxml/xmlversion.h>
... no
need libxml
*** 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.