This is how I integrate rusty tags in my .zprofile:
# rusty-tags
[ `command -v rustc` ] && RUST_SRC_PATH=$(rustc --print sysroot)/lib/rustlib/src/rust/library/
[ -d $RUST_SRC_PATH ] && export RUST_SRC_PATH
I still prefer #ctags over LSP.
#rust #rustlang