Hi, swift-corelibs-dev. I'm planning to land the changes for SE-0055: Making pointer nullability explicit <https://github.com/apple/swift-evolution/blob/master/proposals/0055-optional-unsafe-pointers.md> this afternoon in the Swift compiler; however, the corresponding diff for Foundation is fairly large (PR #304 <https://github.com/apple/swift-corelibs-foundation/pull/304>). Because of this, we've decided to hold off on migrating Foundation to the new model for UnsafePointer, so that it can be reviewed at leisure. This means that for a period of time, swift-corelibs-foundation will not build against the 'master' branch of the compiler. Instead, we're going to make a branch today that's passed all the CI checks, and use that for regression-testing (and building) Foundation for now.
Mishal, Jacob, or I will send a follow-up email once the compiler branch has been created, and another once CI has been updated.