I tried to compile IronRuby on OS X (leopard) with the dmg I downloaded from the mono website, and that didn’t work.
I then uninstalled that mono version by running monoUninstall.sh and proceeded to get mono from subversion. I’m putting these steps on my blog more for future reference when I decide to reinstall my box for some reason.
Download gettext, pkgconfig and glib2.0
extract the archives and build them in the following order gettext, pkgconfig, glib2.0
./configure –prefix=/opt/local
make
sudo make install
At this point it would be wise to set the PKG_CONFIG_PATH environment variable. I added the following line to ~/.bash_profile
export PKG_CONFIG_PATH=”/usr/local/lib/pkgconfig:/opt/local/lib/pkgconfig”
next it’s time to check out the mono sources from their repositories
cd ~/
mkdir tools
mkdir mono
svn co svn://anonsvn.mono-project.com/source/trunk/mono
svn co svn://anonsvn.mono-project.com/source/trunk/mcs
svn co svn://anonsvn.mono-project.com/source/trunk/libgdiplus
svn co svn://anonsvn.mono-project.com/source/trunk/moon
svn co svn://anonsvn.mono-project.com/source/trunk/olive
svn co svn://anonsvn.mono-project.com/source/trunk/gtk-sharp
checking those out will take a while
now go into the mono directory and build mono
cd mono
./autogen.sh –prefix=/opt/local/mono –with-preview=yes –with-moonlight=yes
–with-preview enables the .NET 3.5 features that have been implemented so far
–with-moonlight enables support for moonlight
make
sudo make install
This will also take some time and when it completes you can check if mono is installed by typing mono -V
That’s it for mono, now onto IronRuby
cd ~/tools
svn co http://ironruby.rubyforge.org/svn/trunk ironruby
sudo gem install pathname2
rake compile mono=1
And that should be all 
UPDATE: I’ve got new instructions for building IronRuby
by 
February 7, 2008 at 12:31
I’ve tried the procedure above on Tiger 10.4.8 and it didn’t work. I had to manually set the include and lib folders when building glib2.0 because it wouldn’t look into /opt/local even if the –prefix option was specified, and that in the end worked.
The autogen command for building mono failed miserably:
Running automake –gnu …
aclocal.m4:1078: required file `./ltmain.sh’ not found
mono/profiler/Makefile.am:22: invalid unused variable name: `libmono_profiler_logging_la_LIBADD’
mono/profiler/Makefile.am:21: invalid unused variable name: `libmono_profiler_logging_la_SOURCES’
**Error**: automake failed.
February 11, 2008 at 23:22
Hi Ivan,
How did you get gettext successfully on Leopard? I keep failing on some kind of emacs dependency. It seems this is a common error too – I have found a few references to this so far. It’s a “Fatal malloc_jumpstart()” error.
Did you not encounter this? If you did, how did you get around it?
D.
February 11, 2008 at 23:25
I think the only other thing I have done is to install the XCode tools.
I may have installed gettext once before using ports so that might have solved some of the dependencies I needed.
Otherwise i really can’t say
March 20, 2008 at 04:56
[...] Ivan Porto Carrero posted an update on his upcoming book, IronRuby in Action. Ivan also posts about a good looking IDE theme for Ruby in Steel, and building IronRuby and Mono in Leopard. [...]
March 23, 2008 at 11:45
does anyone knows if there is any other information about this subject in other languages?
May 7, 2008 at 04:56
I got it working with the packaged version of Mono (v1.9.1) by adding the following to my ~/.bash_profile
export PKG_CONFIG_PATH=”/Library/Frameworks/Mono.framework/Libraries/pkgconfig/”
Notice that the current version of IronRuby (rev. 101) wont compile, so you will have to fetch rev. 98 for now.
May 7, 2008 at 21:36
[...] Ivan Porto Carrero: Compiling Mono and IronRuby on OSX Leopard [...]
July 15, 2008 at 15:11
[...] for sure. I downloaded and compiled mono, which was a bit of a pain but I basically followed this post. I recommend you just download the dmg instead (more on that later). Then I got the SDK, which is [...]
December 30, 2008 at 21:36
[...] It won’t work with the latest release of mono. I’m using the trunk version of mono to build ironruby. I’ve got instructions that could show you how to compile mono here. [...]