Xcode 9.3 adds a new IDEWorkspaceChecks.plist file to a workspace's shared data, to store the state of necessary workspace checks. Committing this file to source control will prevent unnecessary rerunning of those checks for each user opening the workspace. (37293167)

これかな。 https://developer.apple.com/library/archive/releasenotes/DeveloperTools/RN-Xcode/Chapters/Introduction.html こんな古くからあったのか。