fastlane: fastlane gym produces error: method `to_plist' not defined in Array

New Issue Checklist

• Updated fastlane to the latest version
• I read the Contribution Guidelines
• I read docs.fastlane.tools
• I searched for existing GitHub issues

Issue Description

On latest version of fastlane, I cannot build anymore build fails, here is the output.

Complete output when running fastlane, including the stack trace and command used

fastlane action gym
[⠼] 🚀 /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/spaceship/lib/spaceship/test_flight/build.rb:87: warning: already initialized constant Spaceship::TestFlight::Build::BUILD_STATES
/Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/spaceship/lib/spaceship/test_flight/build.rb:87: warning: previous definition of BUILD_STATES was here
[✔] 🚀
/Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/credentials_manager/lib/credentials_manager/account_manager.rb:8: warning: already initialized constant CredentialsManager::AccountManager::DEFAULT_PREFIX
/Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/credentials_manager/lib/credentials_manager/account_manager.rb:8: warning: previous definition of DEFAULT_PREFIX was here
Loading documentation for gym:

+----------------------------------------------+
|                     gym                      |
+----------------------------------------------+
| Alias for the `build_ios_app` action         |
|                                              |
| More information: https://fastlane.tools/gym |
|                                              |
| Created by KrauseFx                          |
+----------------------------------------------+


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Run `fastlane env` to append the fastlane environment to your issue
/Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane_core/lib/fastlane_core/core_ext/cfpropertylist.rb:16:in `remove_method': [!] method `to_plist' not defined in Array (NameError)
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane_core/lib/fastlane_core/core_ext/cfpropertylist.rb:16:in `block in <top (required)>'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane_core/lib/fastlane_core/core_ext/cfpropertylist.rb:14:in `each'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane_core/lib/fastlane_core/core_ext/cfpropertylist.rb:14:in `<top (required)>'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/gym/lib/gym/detect_values.rb:1:in `require'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/gym/lib/gym/detect_values.rb:1:in `<top (required)>'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/gym/lib/gym/module.rb:3:in `require_relative'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/gym/lib/gym/module.rb:3:in `<top (required)>'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/gym/lib/gym/manager.rb:2:in `require_relative'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/gym/lib/gym/manager.rb:2:in `<top (required)>'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/gym/lib/gym.rb:1:in `require_relative'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/gym/lib/gym.rb:1:in `<top (required)>'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/actions/build_ios_app.rb:105:in `require'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/actions/build_ios_app.rb:105:in `available_options'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/documentation/actions_list.rb:127:in `print_options'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/documentation/actions_list.rb:60:in `show_details'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/documentation/actions_list.rb:6:in `run'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/commands_generator.rb:246:in `block (2 levels) in run'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/commander-fastlane-4.4.5/lib/commander/command.rb:178:in `call'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/commander-fastlane-4.4.5/lib/commander/command.rb:153:in `run'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/commander-fastlane-4.4.5/lib/commander/runner.rb:476:in `run_active_command'
	from /Users/user/.rvm/rubies/ruby-2.3.3/lib/ruby/gems/2.3.0/gems/fastlane-2.75.1/fastlane_core/lib/fastlane_core/ui/fastlane_runner.rb:75:in `run!'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/commander-fastlane-4.4.5/lib/commander/delegates.rb:15:in `run!'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/commands_generator.rb:336:in `run'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/commands_generator.rb:42:in `start'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/fastlane/lib/fastlane/cli_tools_distributor.rb:94:in `take_off'
	from /Users/user/.rvm/gems/ruby-2.3.3@global/gems/fastlane-2.75.1/bin/fastlane:20:in `<top (required)>'
	from /Users/user/.rvm/gems/ruby-2.3.3/bin/fastlane:22:in `load'
	from /Users/user/.rvm/gems/ruby-2.3.3/bin/fastlane:22:in `<main>'
	from /Users/user/.rvm/gems/ruby-2.3.3/bin/ruby_executable_hooks:15:in `eval'
	from /Users/user/.rvm/gems/ruby-2.3.3/bin/ruby_executable_hooks:15:in `<main>'

Environment

# More information: https://github.com/fastlane/fastlane/tree/master/fastlane/docs
fastlane_version "1.108.0"

ENV["APP_NAME"] = "MyApp"
ENV["INFOPLIST_FILE"] = "MyApp/MyApp-Info.plist"
ENV["SETTINGS_BUNDLE_ROOT"] = "MyApp/Settings.bundle/Root.plist"
ENV["XCODEPROJ"] = "MyApp.xcodeproj"
ENV["WORKSPACE"] = "MyApp.xcworkspace"
ENV["SCHEME_ADHOC"] = "MyApp ADHOC"
ENV["SCHEME_RELEASE"] = "MyApp Release"
ENV["OUTPUT_DIRECTORY"] = "~/Desktop/MyApp"
ENV["TEAM_COMPANY"] = "XXXXXXXXXX"

desc "Called before every lane"
before_all do
    # get the version number
    ENV["VERSION_NUMBER"] = get_version_number(xcodeproj: ENV["XCODEPROJ"])
end

desc "Build a new ipa for dev"
lane :dev do
  build(base_url: "http://<redacted>/api", scheme: ENV["SCHEME_ADHOC"], environment:  "dev")
end

desc "Build a new ipa for qa"
lane :staging do
  build(base_url: "http://<redacted>/api", scheme: ENV["SCHEME_ADHOC"], environment:  "qa")
end

desc "Build a new ipa for training/formation"
lane :training do
  build(base_url: "http://<redacted>/api", scheme: ENV["SCHEME_ADHOC"], environment: "training")
end

desc "Build a new ipa for production"
lane :production do
  build(base_url: "http://<redacted>/api", scheme: ENV["SCHEME_RELEASE"], environment: "production")
end

desc "Build a new ipa whith given options"
private_lane :build do |options|
  # check git status
  #ensure_git_status_clean

  # set base url
  sh("cd .. && /usr/libexec/PlistBuddy \"" + ENV["SETTINGS_BUNDLE_ROOT"] + "\" -c \"set PreferenceSpecifiers:1:DefaultValue " + options[:base_url] + "\"")

  # build the archive and ipa
  output_name_suffix = options[:environment].downcase
  gym(
    workspace: ENV["WORKSPACE"], 
    scheme: options[:scheme], 
    include_bitcode: false, 
    clean: true, 
    silent: false, 
    export_method: "enterprise", 
    export_xcargs: "-allowProvisioningUpdates",
    output_directory: ENV["OUTPUT_DIRECTORY"] + "/" + ENV["VERSION_NUMBER"], # e.g ~/Desktop/MyApp/1.0.0
    output_name: ENV["APP_NAME"] + "-" + ENV["VERSION_NUMBER"] + "-" + output_name_suffix + ".ipa" # e.g. MyApp-1.0.0-production.ipa
  )

  # cleanup
  #reset_git_repo
end

desc "Bump both version numbers"
lane :bump do
  # check git status
  ensure_git_status_clean

  # increment version number
  version = increment_version_number

  # set identical version and build numbers
  set_info_plist_value(path: ENV["INFOPLIST_FILE"], key: "CFBundleVersion", value: version)

  # commit version bump
  git_commit(
    path: [ENV["INFOPLIST_FILE"]], 
    message: "Bump version number"
  )

  # push version bump
  push_to_git_remote()

  # cleanup
  reset_git_repo
end

desc "Build all"
lane :build_all do
	dev
  staging
  training
  production
end

desc "Bump and build all"
lane :bump_build_all do
  bump
  build_all
end

after_all do |lane|
  # display notification
  notification(
    title: ENV["APP_NAME"], 
    subtitle: "Lane '#{lane}' completed successfully!", 
    message: "Grab a beer 🍺"
  )
end

error do |lane, exception|
  # clean
  clean_build_artifacts
  reset_git_repo

  # show how angry you are
  puts "\n(╯°□°）╯︵ ┻━┻\n".red

  # display notification
  notification(
    title: ENV["APP_NAME"], 
    subtitle: "Lane '#{lane}' failed miserably!", 
    message: exception.message
  )
end

app_identifier "com.company.myapp" # The bundle identifier of your app
apple_id "user@company.com" # Your Apple email address

team_id "XXXXXXXXXX"  # Developer Portal Team ID

# you can even provide different app identifiers, Apple IDs and team names per lane:
# More information: https://github.com/fastlane/fastlane/blob/master/fastlane/docs/Appfile.md