no implicit conversion of nil into String

[!] An error occurred while processing the post-install hook of the Podfile.

no implicit conversion of nil into String

/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/pathname.rb:349:in `initialize'
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/pathname.rb:349:in `new'
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/pathname.rb:349:in `+'
/Library/Ruby/Gems/2.3.0/gems/xcodeproj-1.8.1/lib/xcodeproj/project.rb:103:in `open'
/Users/xxx/Documents/WorkCode/DoorCamera/mihomeinternal/MiHome/SegmentPodfile/pre_and_post_install.rb:20:in `block in pod_pre_post_install'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-core-1.6.1/lib/cocoapods-core/podfile.rb:179:in `post_install!'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/installer.rb:701:in `run_podfile_post_install_hook'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/installer.rb:689:in `block in run_podfile_post_install_hooks'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/user_interface.rb:145:in `message'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/installer.rb:688:in `run_podfile_post_install_hooks'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/installer.rb:211:in `block in generate_pods_project'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/user_interface.rb:64:in `section'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/installer.rb:208:in `generate_pods_project'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/installer.rb:139:in `install!'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/command/install.rb:48:in `run'
/Library/Ruby/Gems/2.3.0/gems/claide-1.0.2/lib/claide/command.rb:334:in `run'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/lib/cocoapods/command.rb:52:in `run'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.6.1/bin/pod:55:in `<top (required)>'
/usr/local/bin/pod:23:in `load'
/usr/local/bin/pod:23:in `<main>'
[!] An