Which Swift is Xcode 12 Beta 5 using

How do I find out which Swift snapshot the Xcode 12 Beta 5 (12A8189h) is using? Is there a branch or a tag on the main repo on GitHub?

Sorry if this is in the wrong section, I didn't know where to post this question.

You could use the release/5.3 branch as a close approximation. The compiler in Xcode isn't built directly from GitHub, so there's no tag which you can use to get a bit-by-bit identical compiler.