wrapper.rb

require 'pry'
require 'pry-exception_explorer'
require 'pry-exception_explorer/shim_builder'

binary_name = "lib_overrides.#{PryExceptionExplorer::ShimBuilder::Dyname}"

if !File.exists? File.join PryExceptionExplorer::ShimBuilder.dir, binary_name
  puts "First run, building shim"
  PryExceptionExplorer::ShimBuilder.compile
  puts "Hopefully built...!"
end

if RUBY_PLATFORM =~ /darwin/
  ENV['DYLD_FORCE_FLAT_NAMESPACE'] = "1"
  ENV['DYLD_INSERT_LIBRARIES'] = File.join PryExceptionExplorer::ShimBuilder.dir, binary_name
else
  ENV['LD_PRELOAD'] = File.join PryExceptionExplorer::ShimBuilder.dir, binary_name
end

exec 'rails server' # or whatever