Installing visualruby on Win 7 fails with extconf.rb failed

I am trying to install the visualruby gem on Windows 7 (64 bit, but
running 32-bit Ruby 1.9.3 (ruby 1.9.3p448 (2013-06-27) [i386-mingw32]).

The last line before failure is:

checking for rb_cairo.h… no

and then it fails with:

*** 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.

I have installed the VisualRuby and all it’s prerequisites as described
here:, including GTK2 (gtk2
(2.2.4 x86-mingw32)).

Do I need to set any of the configuration options? I see cairo.h is
located in the following folder:


But none of the configuration options seem to specifically address