>>>>> "a" == aschneiderman <aschneiderman / my-deja.com> writes: a> /cygdrive/c/RUBY/lib/tcltklib.rb:7:in `+': failed to convert nil into a> String (TypeError) tcltklib.rb is pigeon% cat tcltklib.rb require 'tcltklib' + case ENV['TCL_LIBRARY'] when /8\.(\d)/ '8' + $1 when /7\.6/ '76' end pigeon% Do you have defined the environment variable TCL_LIBRARY ? You have 4 libraries pigeon% ls tcl*dll tcltklib76.dll tcltklib81.dll tcltklib82.dll tcltklib83.dll pigeon% Guy Decoux