我正在尝试在 OSX 上安装 Visual Ruby。按照 VisualRuby.net 上的指南，我做了以下事情。
brew install gtk+
然后：
brew install gtksourceview
最后：
sudo gem install visualruby
这会产生以下错误消息。我不知道出了什么问题，有什么想法吗？
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