Error installing debugger-linecache in Ruby 1.9.3

this may help you, it works for me

gem install debugger-linecache -v '1.1.2' -- --with-ruby-include=$rvm_path/src/ruby-1.9.3-p286/

ruby rubygems gem ruby-1.9.3

This error means that the selected version of debugger does not support your current Ruby version. There are two solutions:

Update the debugger gem via bundle update debugger. New versions of debugger are backward-compatible with old Ruby versions, so this is the best way to fix it.
Downgrade your Ruby version.

ruby rubygems gem ruby-1.9.3

Update/Install the gem debugger-ruby_core_source,

gem install debugger-ruby_core_source

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