Uh. What about all the other places where the file checks for self.errors - i.e. completed(), status(), refresh()? This isn't going to do the right thing there, is it? The disk_errors will be disregarded.
These errors are specific just for the case when your disk selection is "wrong". The `checkDiskSelection` method returns errors only if you select just subset of disks with raid/lvm/btrfs. In this case you need either to select them all or quit the installation. It is not possible to leave the `StorageSpoke` with this selection and the check is performed every time you try to leave it (using the "Done" button).