What does the error message "iOS Swift Missing Required Module LegacyCoreKit UnitTest XCTest" mean?

edit

The error message "iOS Swift Missing Required Module LegacyCoreKit UnitTest XCTest" means that the LegacyCoreKit and XCTest modules, which are required for unit testing in iOS Swift, are missing from the project. This can happen if the modules were not included when setting up the project or if they were accidentally removed during development. To resolve the error, the missing modules need to be added back into the project.