Three days after the last macOS High Sierra 10.13.1 beta, Apple has issued another one for developers with a very small increment in build numbers.
Thursday's High Sierra has a build number of 17B46a -- an increment of only one digit after Monday's. The iOS 11 beta release on Monday at the same time as the fourth High Sierra beta was only an increment of one digit from the previous, so the pair of operating systems are likely imminent.
It is unclear at this time what has been changed or added.
Apple last updated macOS High Sierra on Oct. 6 with a supplemental release designed to patch critical Disk Utility and Keychain vulnerabilities. The update also fixed a mail deletion issue in Mail and a graphical bug seen when using Adobe InDesign.
High Sierra debuted in September with marquee features like the new Apple File System (APFS), support for Metal 2 graphics, H.265 integration, an improved Safari experience and more.