xcode14 pod update 的时候报错:

([Xcodeproj] Unknown object version (56). (RuntimeError))

Analyzing dependencies
/Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/user_interface/error_report.rb:34:in `force_encoding': can't modify frozen String (FrozenError)
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/user_interface/error_report.rb:34:in `report'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/command.rb:66:in `report_error'
from /Library/Ruby/Gems/2.6.0/gems/claide-1.0.3/lib/claide/command.rb:396:in `handle_exception'
from /Library/Ruby/Gems/2.6.0/gems/claide-1.0.3/lib/claide/command.rb:337:in `rescue in run'
from /Library/Ruby/Gems/2.6.0/gems/claide-1.0.3/lib/claide/command.rb:324:in `run'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/command.rb:52:in `run'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/bin/pod:55:in `<top (required)>'
from /usr/local/bin/pod:23:in `load'
from /usr/local/bin/pod:23:in `<main>'
/Library/Ruby/Gems/2.6.0/gems/xcodeproj-1.21.0/lib/xcodeproj/project.rb:228:in `initialize_from_file': [Xcodeproj] Unknown object version (56). (RuntimeError)
from /Library/Ruby/Gems/2.6.0/gems/xcodeproj-1.21.0/lib/xcodeproj/project.rb:113:in `open'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer/analyzer.rb:1190:in `block (2 levels) in inspect_targets_to_integrate'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer/analyzer.rb:1189:in `each'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer/analyzer.rb:1189:in `block in inspect_targets_to_integrate'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/user_interface.rb:64:in `section'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer/analyzer.rb:1184:in `inspect_targets_to_integrate'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer/analyzer.rb:106:in `analyze'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer.rb:416:in `analyze'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer.rb:241:in `block in resolve_dependencies'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/user_interface.rb:64:in `section'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer.rb:240:in `resolve_dependencies'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/installer.rb:161:in `install!'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/command/install.rb:52:in `run'
from /Library/Ruby/Gems/2.6.0/gems/claide-1.0.3/lib/claide/command.rb:334:in `run'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/lib/cocoapods/command.rb:52:in `run'
from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.11.3/bin/pod:55:in `<top (required)>'
from /usr/local/bin/pod:23:in `load'
from /usr/local/bin/pod:23:in `<main>'

这个问题一般是发生在Xcode升级后,新建的项目pod install, 然后 pod update

解决方法

把Project Format改到低版本然后pod update