Joining a new project, I had to go through the usual setting-up rigmarole - which means finding several new things to break/configure/reinstall. One of which was to get soap4r to run.
I'd run gem install soap4r just fine, but running rake was giving me the error below:
rake aborted! uninitialized constant SOAP::Mapping::EncodedRegistry
Scrounging around gave several solutions that didn't work, mainly using two of the three lines below. I required all three of the following before it ran for me.
# Add these lines to config/environment.rb just before the Rails initializer code require 'rubygems' gem 'soap4r' require 'soap/mapping'