Apple has moved on to its second round of betas for its milestone releases, offering developers new builds of iOS 13, iPadOS 13, tvOS 13, watchOS 6 and macOS 10.15 Catalina for testing.
The new builds can be acquired by developers in the beta as an over-the-air update on devices enrolled into the program, or via the Apple Developer Center. Public beta versions of each operating system normally arrive a few days after the developer betas, though so far they have not been made available for the milestone versions, and are made available via the Apple Beta Software Program website.
The second developer test version of iOS 13 is build number 17A5508m, replacing the first beta, build 17A5492t. The second tvOS 13 beta is build 17J5501l, up from 17J5485s for the first build. The new second watchOS 6 build is 17R5507l, taking over from the first, 17R5491t. The second iPadOS 13 beta is build 17A5508m Lastly, macOS Catalina 10.15's second build is 19A487l, carrying on from the first build, 19A471t.
The new batch of beta builds arrive within a few weeks of the first, which were issued shortly after Apple presented the new operating system versions on June 3 at WWDC.
Apple is currently running two separate sets of betas at the same time, with the milestone operating systems offered alongside iOS 12.4, tvOS 12.4, watchOS 5.3, and macOS 10.14.6.
AppleInsider, and Apple itself, strongly suggest users avoid installing betas on to "mission-critical" or primary devices, due to the potential for data loss or other issues. It is instead recommended to install betas onto secondary or non-essential devices, and to ensure there are sufficient backups of important data beforehand.