Gem::InstallerでErrno::EPERM: Operation not permittedが出るときの逃げ道

gem_installer_eperm_patch.rb

# monkey patch for permission problem when installing package including executables from git repository
# (Errno::EPERM: Operation not permitted)
# for rubygems >= 1.8

# 1. put this file under lib directory.
# 2. put below line to top of Gemfile.
#
#    require File.expand_path("lib/gem_installer_eperm_patch", File.dirname(__FILE__))
#
require 'rubygems/installer'

class Gem::Installer
  def generate_bin
    return if spec.executables.nil? or spec.executables.empty?

    # If the user has asked for the gem to be installed in a directory that is
    # the system gem directory, then use the system bin directory, else create
    # (or use) a new bin dir under the gem_home.
    bindir = @bin_dir || Gem.bindir(gem_home)

    Dir.mkdir bindir unless File.exist? bindir
    raise Gem::FilePermissionError.new(bindir) unless File.writable? bindir

    spec.executables.each do |filename|
      filename.untaint
      bin_path = File.expand_path File.join(gem_dir, spec.bindir, filename)

      unless File.exist? bin_path
        warn "Hey?!?! Where did #{bin_path} go??"
        next
      end

      if File.owned?(bin_path)
        mode = File.stat(bin_path).mode | 0111
        FileUtils.chmod mode, bin_path

        if @wrappers then
          generate_bin_script filename, bindir
        else
          generate_bin_symlink filename, bindir
        end
      else
        warn "#{bin_path} is owned by different user. chmod skipped."
      end
    end
  end
end