Same here - I’m using LLDB shipped with Xcode 7.3 on Mac OS X 10.11.4 (latest at the point of writing). The ‘frame variable’ debugger command shows nothing, nor does ‘print’ with an explict symbol name. It doesn’t matter if I start LLDB directly or via the ‘rust-lldb’ script. GDB installed via Homebrew works in that it correctly lists locals for a stack frame and shows their values, pretty-printed or otherwise.
Using Linux virtual machines, I’ve confirmed that both LLDB (3.4 on Ubuntu 14.04 LTS, 3.7 on Fedora 23 Workstation) and GDB work (see above for definition of ‘work’) on Linux.
I’ve yet to try using a different LLDB version on a Mac - I’d rather avoid that, given that the one shipped by Apple seems recent. If I end up doing that, I’ll post the exact version numbers used.
And the LLDB version shipped by Apple is lldb-3184.108.40.206. I’ve built the latest LLDB from source - its version number is lldb-360.99.0 - and it doesn’t work either. I’m currently debugging the latter with the former, as this is not necessarily a Rust problem, it may be actually be specific to LLDB on Mac OS X with non-clang languages.