libxml-ruby failed to build native extensions

Question

I'm using ruby 2.1.10 on El Capitan and trying to install libxml-ruby -v '2.7.0'.

when I run gem install libxml-ruby -v '2.7.0 I get this

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

    /Users/stuartpearman/.rvm/rubies/ruby-2.1.10/bin/ruby -r ./siteconf20160527-15602-1pq16mj.rb extconf.rb
checking for socket() in -lsocket... no
checking for gethostbyname() in -lnsl... no
checking for atan() in -lm... yes
checking for inflate() in -lz... yes
checking for iconv_open() in -liconv... yes
checking for xmlParseDoc() in -lxml2... yes
checking for libxml/xmlversion.h... yes
checking for rb_io_bufwrite() in ruby/io.h... yes
creating extconf.h
creating Makefile

make "DESTDIR=" clean

make "DESTDIR="
compiling libxml.c
compiling ruby_xml.c
ruby_xml.c:612:23: warning: assigning to 'const char *' from 'xmlChar *' (aka 'unsigned char *') converts between pointers to integer types with different sign [-Wpointer-sign]
  xmlTreeIndentString = xmlStrdup((xmlChar *)StringValuePtr(string));
                      ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
compiling ruby_xml_attr.c
compiling ruby_xml_attr_decl.c
ruby_xml_attr_decl.c:57:53: warning: passing 'const xmlChar *' (aka 'const unsigned char *') to parameter of type 'const char *' converts between pointers to integer types with different sign [-Wpointer-sign]
    return rxml_new_cstr((const char*) xattr->name, xattr->doc->encoding);
                                                    ^~~~~~~~~~~~~~~~~~~~
./ruby_xml_encoding.h:11:51: note: passing argument to parameter 'xencoding' here
VALUE rxml_new_cstr(const char* xstr, const char* xencoding);
                                                  ^

The full error is about 600 lines, but is more of the same.

I've scoured the internet for a solution and tried many different things, but had no luck. Any ideas?

Answer 1

The problem was that I did not have a few necessary utilities installed on my mac.

I fixed this by running a few brew installs:

brew install libxml2 libxslt

and

brew install coreutils

After installing coreutils, a lot of issues I was having magically disappeared.

Also, when installing Nokogiri, I had to do something very close to this:

gem install nokogiri --use-system-libraries -- --with-ldflags

Though I can't remember the exact options I used