/usr/local/bin/ruby/ruby-2.5.0/lib/fileutils.rb:1292:in `initialize': Is a directory @ rb_sysopen - /usr/local/bin/ruby (Errno::EISDIR)

This error message indicates that the program is trying to open a directory (/usr/local/bin/ruby), but the rb_sysopen method can only be used to open files.

To fix this error, you should check the code to see if there is an attempt to open a file within that directory. If so, make sure that the correct path to the file is used. If not, you may need to modify the code to handle directories differently than files.