capistrano3-pumaのtaskが読み込めない場合の対応

事象

CapistranoのVersionを3.8にあげると、デプロイが失敗するようになりました。
capistrano3-pumaのtaskがよみこめなくなったというエラーがでます。

Don't know how to build task 'start' (see --tasks)
Don't know how to build task 'puma:restart' (see --tasks)

設定ファイル

config/deploy.rb

namespace :puma do
  desc 'Create Directories for Puma Pids and Socket'
  task :make_dirs do
    on roles(:app) do
      execute "mkdir #{shared_path}/tmp/sockets -p"
      execute "mkdir #{shared_path}/tmp/pids -p"
    end
  end
  before :start, :make_dirs
end

namespace :deploy do

  desc 'Restart application'
  task :restart do
    on roles(:app), in: :sequence, wait: 5 do
      invoke 'puma:restart'
    end
  end

  after :publishing, :restart
end

require "capistrano/setup"
require "capistrano/deploy"
require "capistrano/rails"
require 'capistrano/puma'
require "capistrano/scm/git"

install_plugin Capistrano::SCM::Git

Dir.glob("lib/capistrano/tasks/*.rake").each{|r| import r}

対応

Capfileにinstall_plugin Capistrano::Pumaを追記しました。

require "capistrano/setup"
require "capistrano/deploy"
require "capistrano/rails"
require 'capistrano/puma'
require "capistrano/scm/git"

install_plugin Capistrano::SCM::Git
install_plugin Capistrano::Puma <-コレ

Dir.glob("lib/capistrano/tasks/*.rake").each{|r| import r}

追記

さらに最新(2017/06/07)のcapistrano3-pumaのGemをinstallすると、またもやエラーが発生

Skipping task `puma:restart'.
Capistrano tasks may only be invoked once. Since task `puma:restart' was previously invoked, invoke("puma:restart") at rails_app/vendor/bundle/ruby/2.4.0/gems/capistrano3-puma-3.1.0/lib/capistrano/tasks/puma.rake:96 will be skipped.
If you really meant to run this task again, first call Rake::Task["puma:restart"].reenable
THIS BEHAVIOR MAY CHANGE IN A FUTURE VERSION OF CAPISTRANO. Please join the conversation here if this affects you.
https://github.com/capistrano/capistrano/issues/1686

対応

config/deploy.rb

namespace :deploy do

  desc 'Restart application'
  task :restart do
    on roles(:app), in: :sequence, wait: 5 do
      Rake::Task["puma:restart"].reenable <-コレを追記
      invoke 'puma:restart'
    end
  end

#  after :finishing, :restart <- これをコメントアウトする

参考

https://stackoverflow.com/questions/43014993/dont-know-how-to-build-task-start-when-run-cap-production-deploy-for-capist
https://github.com/seuros/capistrano-puma#usage
https://github.com/capistrano/capistrano/issues/1686
https://stackoverflow.com/questions/39810930/pumarestart-invoke-twice-but-i-only-call-it-once-on-my-deploy-app-via-capistr