I thought /opt/local/bin was the same as /private/opt/local/bin
but it isn't.

I had to add it to the path and then newcocoa was found.
I have 3 rubycocoas

/usr/lib/ruby182/site_ruby/1.8/powerpc-darwin8.0/rubycocoa.bundle

/private/opt/local/lib/ruby/site_ruby/1.8/powerpc-darwin8.3.0/
rubycocoa.bundle

/usr/local/lib/ruby/site_ruby/1.8/powerpc-darwin8.7.0/rubycocoa.bundle

$PATH
 /opt/local/bin:/opt/local/lib:/opt/local/sbin:/usr/local/bin:/usr/
local/sbin:/private/opt/local/bin:/private/opt/local/lib:/private/opt/
local/sbin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/mysql/bin/:

I seem to have all possible paths on there, but newcocoa is still
having trouble. How do I find what the trouble is?

newcocoa -c
["English.lproj/Main.nib"]
Generating class skeltons from  `English.lproj/Main.nib' ...
/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require': no such file to load -- osx/cocoa (LoadError)
        from /opt/local/lib/ruby/site_ruby/1.8/rubygems/
custom_require.rb:27:in `require'
        from /opt/local/lib/ruby/gems/1.8/gems/newcocoa-0.0.4/bin/
newcocoa:25:in `convert'
        from /opt/local/lib/ruby/gems/1.8/gems/newcocoa-0.0.4/bin/
newcocoa:66
        from /opt/local/lib/ruby/gems/1.8/gems/newcocoa-0.0.4/bin/
newcocoa:64:in `each'
        from /opt/local/lib/ruby/gems/1.8/gems/newcocoa-0.0.4/bin/
newcocoa:64
        from /opt/local/bin/newcocoa:16:in `load'
        from /opt/local/bin/newcocoa:16