lldb target/debug/rust or
rust-lldb target/debug/rust from the VS Code Terminal will open the debugger, but running the program (with or without breakpoint at the main function) returns:
error: process exited with status -1 (attach failed ((os/kern) invalid argument))
I'm running on Mac M1. Running the same stuff from Mac Terminal works fine.
From VS Code Terminal:
% which lldb
% which rust-lldb
which is the same as Mac Terminal.