def write_env
      FileUtils.mkdir_p proc_dir

      procfile_entries.each do |process|
        process_file = File.join(proc_dir, process.name)

        File.open(process_file, "w+") do |f|
          f.puts "#!/bin/sh"
          f << "exec "
          f << process.command
          f << " $@"
        end

        FileUtils.chmod 0755, process_file
      end
    end
def write_env
      FileUtils.mkdir_p proc_dir

      procfile_entries.each do |process|
        process_file = File.join(proc_dir, process.name)

        File.open(process_file, "w+") do |f|
          f.puts "#!/bin/sh"
          f << "exec "
          f << process.command
          f << " $@"
        end

        FileUtils.chmod 0755, process_file
      end
    end
Parses the output of buildpack/bin/release executable to find out its default Procfile commands.
 Then merges those with the ones from the app's Procfile (if any).
 Finally, generates a binstub in vendor/pkgr/processes/ so that these commands can be called using the app's executable.