Error on installing Visual Ruby on OSX

Question

I am trying to install Visual Ruby on OSX. Following the guide on VisualRuby.net I did the following.

brew install gtk+

then:

brew install gtksourceview

and finally:

sudo gem install visualruby

which yields the following error message. I have no idea what is wrong, any ideas?

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

        /Users/ma/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb
checking for -Wall option to compiler... yes
checking for -Waggregate-return option to compiler... yes
checking for -Wcast-align option to compiler... yes
checking for -Wextra option to compiler... yes
checking for -Wformat=2 option to compiler... yes
checking for -Winit-self option to compiler... yes
checking for -Wlarger-than-65500 option to compiler... yes
checking for -Wmissing-declarations option to compiler... yes
checking for -Wmissing-format-attribute option to compiler... yes
checking for -Wmissing-include-dirs option to compiler... yes
checking for -Wmissing-noreturn option to compiler... yes
checking for -Wmissing-prototypes option to compiler... yes
checking for -Wnested-externs option to compiler... yes
checking for -Wold-style-definition option to compiler... yes
checking for -Wpacked option to compiler... yes
checking for -Wp,-D_FORTIFY_SOURCE=2 option to compiler... yes
checking for -Wpointer-arith option to compiler... yes
checking for -Wswitch-default option to compiler... yes
checking for -Wswitch-enum option to compiler... yes
checking for -Wundef option to compiler... yes
checking for -Wunsafe-loop-optimizations option to compiler... yes
checking for -Wwrite-strings option to compiler... yes
checking for rb_define_alloc_func() in ruby.h... yes
checking for rb_block_proc() in ruby.h... yes
checking for new allocation framework... yes
checking for attribute assignment... no
checking for cairo... yes
checking for rb_cairo.h... yes
checking for Win32 OS... no
checking for gtksourceview-2.0... yes
*** 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.

Provided configuration options:
    --with-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/Users/ma/.rvm/rubies/ruby-1.9.3-p194/bin/ruby
    --with-pkg-config
    --without-pkg-config
    --with-override-variables
    --without-override-variables
/Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:239:in `parse_pc': .pc for libxml-2.0 doesn't exist. (RuntimeError)
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:181:in `declaration'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:130:in `requires_private'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:311:in `all_required_packages'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:195:in `collect_cflags'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:134:in `cflags'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:196:in `block in collect_cflags'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:195:in `collect'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:195:in `collect_cflags'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:134:in `cflags'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:364:in `cflags'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/pkg-config-1.1.4/lib/pkg-config.rb:415:in `have_package'
    from /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/glib2-1.1.5/lib/mkmf-gnome2.rb:540:in `required_pkg_config_package'
    from extconf.rb:58:in `<main>'


Gem files will remain installed in /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/gtksourceview2-1.1.5 for inspection.
Results logged to /Users/ma/.rvm/gems/ruby-1.9.3-p194/gems/gtksourceview2-1.1.5/ext/gtksourceview2/gem_make.out

Answer 1

Try brew update You may be encountering this bug if you're running mountain lion.

Answer 2

I ran into the same issue. I found out that Mountain Lion is missing the libxml-2.0.pc file in /usr/lib/pkgconfig as mentioned here.

After ensuring that libxml2 was installed:

brew install libxml2

I created the suggested symlink which allowed me to install VisualRuby.

sudo ln -s /usr/local/Cellar/libxml2/2.9.0/lib/pkgconfig/libxml-2.0.pc /usr/lib/pkgconfig