This looks like CoreStore is being built in swift mode but it hasn’t been updated for 5.
/Users/buildnode/jenkins/workspace-private/swift-master-sourcekitd-stress-tester-weekly/project_cache/CoreStore/Sources/Relationship.swift:213:38: error: add () to forward @autoclosure parameter
versionHashModifier: versionHashModifier,
^~~~~~~~~~~~~~~~~~~
Will file when I get in today.
— Harlan