Dear Aditya, I did what you told me, set RUBYLIB=..../texmf.local/scripts/context/ruby export $RUBYLIB But there is no change in the output of "texmfstart --verbose texexec". I copied texexec.rb in the home directory, then I got ~ mac$ texmfstart --verbose texexec texmfstart version 1.8.6 expanding 'texexec' to 'texexec.rb' locating 'texexec.rb' in current path '.' registering 'texexec' as '/Users/mac/texexec.rb' 'texexec.rb' located in current path registering 'THREAD' as '/Users/mac' starting texexec using 'system' call: ruby /Users/mac/texexec.rb /Users/mac/texexec.rb:10:in `require': No such file to load -- base/ switch (LoadError) from /Users/mac/texexec.rb:10 According to this message, it locate texexec.rb. However, the commnad texmfstart texexec --make en did nothing but only a message like this. /Users/mac/texexec.rb:10:in `require': No such file to load -- base/ switch (LoadError) from /Users/mac/texexec.rb:10 Would you please tell me what I have to do more? Thank you for reading. Best regards, Dalyoung