I have been trying to install a Rails app called devalot
(http://software.pmade.com/devalot) on my Mac (10.4 Tiger).  I built
Ruby 1.8.5 from source on this box, and have been using it daily for
weeks for Rails development and other, non-Rails Ruby playing.

In the setup process, it requires a ruby script to run to do some setup:

ruby script/setup.rb

When I run this script, I get this error:

/usr/local/lib/ruby/site_ruby/1.8/digest.rb:16:in `const_missing':
Digest class not found: Digest::SHA384 (NameError)

Now, when I look in /usr/local/lib/ruby/site_ruby/1.8/digest.rb, I
find these lines:

require 'digest.so'

module Digest
  autoload "SHA256", "digest/sha2.so"
  autoload "SHA384", "digest/sha2.so"
  autoload "SHA512", "digest/sha2.so"
...


Now, I don't have any .so files lying around.  I believe the right
things are .bundle files on MacOSX.

I have, in /usr/local/lib/ruby/site_ruby/1.8/i686-darwin8.8.2, a
digest.bundle and a digest/sha2.bundle.  I have the same thing in
/usr/local/lib/ruby/1.8/i686-darwin8.8.2.  I don't know why they're in
both places.  They're not symlinks, and cmp(1) says they're identical
files.  Anyway...

Anyway, can someone tell me what I appear to have done wrong, or what
Ruby did wrong, when I built it to get into this situation?

By way of comparison, the hpricot gem does

  require 'hpricot_scan'

and then there is in its lib dir both 'hpricot_scan.so' and
'hpricot_scan.bundle'.

Any ideas of where to start?