You should use the log crate to automatically log to logcat (on-device) or stdout (on-host):


rust_binary {
    name: "hello_rust_logs",
    crate_name: "hello_rust_logs",
    srcs: ["src/main.rs"],
    rustlibs: [
    host_supported: true,


//! Rust logging demo.

use log::{debug, error, info};

/// Logs a greeting.
fn main() {
    debug!("Starting program.");
    info!("Things are going fine.");
    error!("Something went wrong!");

Build, push, and run the binary on your device:

m hello_rust_logs
adb push "$ANDROID_PRODUCT_OUT/system/bin/hello_rust_logs" /data/local/tmp
adb shell /data/local/tmp/hello_rust_logs

The logs show up in adb logcat:

adb logcat -s rust
09-08 08:38:32.454  2420  2420 D rust: hello_rust_logs: Starting program.
09-08 08:38:32.454  2420  2420 I rust: hello_rust_logs: Things are going fine.
09-08 08:38:32.454  2420  2420 E rust: hello_rust_logs: Something went wrong!