class Bundler::SelfManager

def install_and_restart_with(version)
  requirement = Gem::Requirement.new(version)
  spec = find_latest_matching_spec(requirement)
  if spec.nil?
    Bundler.ui.warn "Your lockfile is locked to a version of bundler (#{lockfile_version}) that doesn't exist at https://rubygems.org/. Going on using #{current_version}"
    return
  end
  install(spec)
rescue StandardError => e
  Bundler.ui.trace e
  Bundler.ui.warn "There was an error installing the locked bundler version (#{lockfile_version}), rerun with the `--verbose` flag for more details. Going on using bundler #{current_version}."
else
  restart_with(version)
end