OSX 10.6 Dependencies - shoes/shoes3 GitHub Wiki
Only a glutton for punishment would do this. If you really do need to build shoes on 10.6 then start with downloading the pre-built dependencies and create your snow-custom.yaml or xsnow-custom.yaml. If you don't know the difference between snow and xsnow, you're not ready to do this.
Did you know that Shoes/OSX 10.6 has an old version of openssl with known exploits and no one is going to fix it? Not Apple, not Ruby, not openssl and certainly not me. You did know that, right? You do now. Only James Kirk believes it's not dead.
You'll also want to read. And you'll know what to do.
But, if you really, really want 10.6 start by getting the prebuilt deps.
Want to rebuild the dependencies yourself go for it - you can use the snow-*.sh to configure.