One of the issues that keeps on rearing its ugly head, and I have never got round to fixing is the following error locally on Textmate:
env: ruby: No such file or directory
Well today I decided to put an end to it!
Textmate assumes (wrongly in my case) that Ruby is located at:
/usr/local/bin/ruby
Whereas a quick check on the terminal with the following command:
which ruby
tells me my ruby version is actually located here:
/opt/local/bin/ruby
Textmate does not know this, there are two routes here, either create a symlink or my preferred option which I will show you below, which is to add a shell variable to Textmates preferences.
Open up Textmate and click on Textmate -> Preferences (or shortcut key apple+,). Then select the Shell Variable Tab.
Add a Shell Variable called TM_RUBY and enter the path to your ruby.

Restart Textmate and you should never see this issue again!
nogeek — November 26, 2009
Quick addendum to this, you also need to add the path to the bin section:
My path is set as (variable:PATH) : /usr/bin:/bin:/usr/sbin:/sbin:/opt/local/bin