@tromey Thanks for the update! It seems that https://github.com/rust-lang/rust/pull/52716 has been merged.
But I am unable to install it with rustup component add lldb-preview --toolchain nightly although it seems that the package available in the toolchain:
https://static.rust-lang.org/dist/2018-08-17/index.html (lldb-nightly-x86_64-apple-darwin.tar.gz)
Is this intended behaviour?