cxx_configuration do source_lib "testme", :sources => FileList['**/*.cpp'], :includes => ['include'], :dependencies => [] # using lambdas custom "testcustom", :execute => lambda { puts "executing testcustom" }, :dependencies => ["testme"] def foo puts "foo for testcustom2" end # using methods custom "testcustom2", :execute => method(:foo), :dependencies => ["testcustom"] # using new lambda syntax custom "testcustom3", :execute => -> { puts "executing testcustom3" }, :dependencies => ["testcustom2"] end