fastlane: Modifing project file with Xcodeproj makes gym not able to find the project file

New Issue Checklist

• Updated fastlane to the latest version
• I have read the Contribution Guidelines

Issue Description

I’m changing some things in the Xcode project before building (see Fastfile excerpt below), and after I save the project, gym is unable to find the project, as if the current path changed. However, it didn’t change, as confirmed with Dir.pwd before and after the project.save command.

If I set the project file manually, the error is

/Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/runner.rb:59:in `chdir': [!] No such file or directory @ dir_chdir - ./fastlane/ (Errno::ENOENT)
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/runner.rb:59:in `rescue in execute'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/runner.rb:44:in `execute'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/lane_manager.rb:46:in `cruise_lane'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/command_line_handler.rb:30:in `handle'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/commands_generator.rb:49:in `block (2 levels) in run'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/commander-4.4.0/lib/commander/command.rb:178:in `call'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/commander-4.4.0/lib/commander/command.rb:178:in `call'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/commander-4.4.0/lib/commander/command.rb:153:in `run'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/commander-4.4.0/lib/commander/runner.rb:444:in `run_active_command'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane_core-0.52.0/lib/fastlane_core/ui/fastlane_runner.rb:36:in `run!'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/commander-4.4.0/lib/commander/delegates.rb:15:in `run!'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/commands_generator.rb:246:in `run'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/commands_generator.rb:20:in `start'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/lib/fastlane/cli_tools_distributor.rb:58:in `take_off'
    from /Users/gcamp/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/fastlane-1.104.0/bin/fastlane:5:in `<top (required)>'
    from /Users/gcamp/.rbenv/versions/2.2.3/bin/fastlane:23:in `load'
    from /Users/gcamp/.rbenv/versions/2.2.3/bin/fastlane:23:in `<main>'

Configuration Files

Fastfile:

def update_transit_target
    require 'xcodeproj'

    project = Xcodeproj::Project.open("../#{XCODE_PROJ}")
    target = project.native_targets.find {|s| s.name == "TransitBeta" }

    yield(target)

    project.save

    gym
end

Environment

fastlane version (run fastlane -v): fastlane 1.104.0

Do you use bundler to execute fastlane (i.e. bundle exec fastlane)? No

Do you use a Ruby environment manager (e.g. chruby, rbenv, rvm)? rbenv