如何在Circleci中添加插件fastlane-plugin-appicon？

Question

我想安装fastlane插件fastlane-plugin-appicon，所以我在circleci文件中添加了添加命令“-run：bundle exec fastlane add_plugin appicon”，但是出了点问题，circleci代码和错误日志如下，谢谢！

beta:
macos:
    xcode: "10.1.0"
    working_directory: /Users/distiller/project
environment:
  FL_OUTPUT_DIR: output
  FASTLANE_LANE: ios beta
shell: /bin/bash --login -o pipefail
steps:
  - checkout
  - run:
      name: pre-start simulator
      command: xcrun instruments -w "iPhone 8 (12.1)" || true
  - run:
      name: Set Ruby Version
      command:  echo "ruby-2.4" > ~/.ruby-version
  - run: brew update
  - run: brew cask install fastlane --no-quarantine
  - run: bundle update fastlane
  - run: bundle exec fastlane add_plugin appicon 
  - run: bundle install --path .bundle
  - run:
     name: Fastlane
     command: bundle exec fastlane $FASTLANE_LANE
  - store_artifacts:
      path: output
  - run:
      name: Transition Jira items for deployment
      command: .circleci/transition-jira-items.sh