Apple today seeded the fifth beta of an upcoming macOS Sierra 10.12.5 update to developers, one week after seeding the fourth beta and more than one month after releasing macOS Sierra 10.12.4, which introduced Night Shift for the Mac.
The fifth beta of macOS Sierra 10.12.5 can be downloaded through the Apple Developer Center or through the Software Update mechanism in the Mac App Store.
According to the release notes accompanying the beta, the update "improves the stability, compatibility, and security of your Mac."
Apple's release notes don't often provide much insight into what's included in new beta software, so we don't know what features or bug fixes might be built into the 10.12.5 update.
No notable changes or major bug fixes were discovered in the first four betas, but should anything pop up in the fifth macOS Sierra 10.12.5 beta, we'll update this post.
Update: The fifth beta of macOS Sierra 10.12.5 is also available for public beta testers.
Source: macrumors