OK, *THAT* was painful...

All I wanted to do was to install merb so that I could work on porting some web services I'd already created under Rails. merb 0.0.8 was already installed in the existing Rails project I was working with, but I needed the latest version (0.1.1) which has the REST support in it.

So, I followed the instructions in the README file, created a new merb app, and fired it up:

$ merb -g myapp
$ cd myapp
$ merb


But all I ever got when I tried to access http://localhost:4000 was an incessant error:

undefined method `each' for nil:NilClass

Man, I tried just about everything to figure out where this was coming from. I had checked the gems it depends on and I had them, but I figured it couldn't hurt to execute the entire gem install line at this point:

$ sudo gem install mongrel erubis json mime-types archive-tar-minitar rspec —include-dependencies

I uninstalled merb 0.1.1 (rake uninstall) and reinstalled it from the freshly-checked-out trunk, then repeated the app creation/run commands once again.

It works.

Moral of the Story: follow directions to the letter, no matter how sure you are you "already have that covered."