In the process of setting up metric_fu, I found that, one way or another, saikuro’s output wasn’t getting into the correct place. I’ll spare you the long story, and just show the config settings I had to put into my Rakefile to get things working: config.saikuro = { :output_directory => “#{ENV["CC_BUILD_ARTIFACTS"]}/scratch/saikuro”, :input_directory => ["app\" --input_directory [...]