This post originated from an RSS feed registered with Ruby Buzz by Eigen Class. Original Post: Cross-compiling Ruby extensions for win32: rcovrt Feed Title: Eigenclass Feed URL: http://feeds.feedburner.com/eigenclass Feed Description: Ruby stuff --- trying to stay away from triviality. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Eigen Class Latest Posts From Eigenclass

It seems that building Ruby extensions under win32 is quite a daunting task: I've been asked repeatedly to provide win32 binaries for rcovrt (the extension that makes rcov's code coverage analysis run two orders of magnitude faster*1), so I cross-compiled it from the comfort of a non-win32 platform, using mingw.

Binaries built with mingw should be compatible with the ruby-mswin32 distribution, which also means they should work fine with the latest one-click-installer distros (the 1.8.4-16 series), since they are based on the good old ruby-mswin32 builds.

Cross-compiling ruby

The first thing I need to generate an appropriate Makefile in order to cross-compile rcovrt is a suitable rbconfig.rb. It turns out that the easiest way to create it is cross-compiling ruby itself (it takes under 2 minutes on my fairly old box), obtaining the desired file in the process.

I wrote a simple cross-compile.sh: