README recommends unoptimized build

[joshtriplett]

Currently, the instructions in README recommend cargo run, which will build and run an unoptimized build (including unoptimized dependencies).

You may want to either recommend cargo run -r for an optimized release build, or modify Cargo.toml such that the default profile (used for cargo run) builds the crate and its dependencies with optimizations.

To do the latter, you could add the following to Cargo.toml:

[profile.dev]
opt-level = 3
debug = "line-tables-only"
debug-assertions = false
overflow-checks = false

See https://doc.rust-lang.org/cargo/reference/profiles.html for more information and other flags you may wish to change (for either dev or release profiles).

[wusyong]

Thanks for the suggestion! I chose the debug build because building the whole application will already take a while.
We build release profiles for nightly releases. I guess we can add more configurations for Cargo.toml in the future.