Rails "Plugin not found" error may be a red herring.

I've been writing a number of plugins lately, and I kept getting this error when I would install it from RubyForge:

Plugin not found: ["http://blah.rubyforge.org/svn/trunk/vendor/plugins/blah"]

I knew the plugin was there, and in fact I could see that the plugin files were being placed in the vendor/plugins directory. So why was this message showing up?

After a number of hours (yes, hours, it's depressing) it turned out that I had an error in my plugin's install.rb file. Apparently any exception raised in a plugin's install.rb file gets caught and the erroneous "Plugin not found:" message is shown.

So, if you see this error and are confused, start adding traces to your install.rb file and you are likely to find something is broken.