Logging and Debugging

nmrs uses the log crate for structured logging. You can enable logging to see what nmrs is doing internally, which is invaluable for debugging connection issues.

Enabling Logging

nmrs produces log messages but doesn't configure a logger — that's up to your application. The simplest option is env_logger:

[dependencies]
nmrs = "2.2"
env_logger = "0.11"
log = "0.4"

use nmrs::NetworkManager;

#[tokio::main]
async fn main() -> nmrs::Result<()> {
    env_logger::init();

    let nm = NetworkManager::new().await?;
    nm.scan_networks().await?;

    Ok(())
}

Run with:

RUST_LOG=nmrs=debug cargo run

Log Levels

Level	Content
`error`	Connection failures, D-Bus errors
`warn`	Unexpected states, fallback behavior
`info`	Connection events, state transitions
`debug`	D-Bus method calls, scan results, settings
`trace`	Raw D-Bus messages, detailed internal state

Level Examples

# Only errors
RUST_LOG=nmrs=error cargo run

# Info and above
RUST_LOG=nmrs=info cargo run

# Full debug output
RUST_LOG=nmrs=debug cargo run

# Everything including D-Bus internals
RUST_LOG=nmrs=trace cargo run

# Debug nmrs + info for zbus
RUST_LOG=nmrs=debug,zbus=info cargo run

Debugging Connection Issues

When a connection fails, enable debug logging to see the full sequence:

RUST_LOG=nmrs=debug cargo run

This will show:

Which device was selected
Whether a saved connection was found
The settings dictionary sent to NetworkManager
State transitions during activation
The specific error or reason for failure

Debugging D-Bus Issues

If you suspect a D-Bus communication problem, enable trace logging for both nmrs and zbus:

RUST_LOG=nmrs=trace,zbus=debug cargo run

You can also use system tools:

# Monitor NetworkManager D-Bus traffic
sudo dbus-monitor --system "interface='org.freedesktop.NetworkManager'"

# Check NetworkManager journal logs
journalctl -u NetworkManager -f

# Check wpa_supplicant logs (for Wi-Fi auth issues)
journalctl -u wpa_supplicant -f

Using with Other Loggers

nmrs works with any logger that implements the log facade:

tracing (with compatibility layer)

[dependencies]
tracing = "0.1"
tracing-subscriber = "0.3"
tracing-log = "0.2"

use tracing_subscriber;

fn main() {
    tracing_subscriber::fmt()
        .with_env_filter("nmrs=debug")
        .init();
    // ...
}

simplelog

[dependencies]
simplelog = "0.12"

use simplelog::*;

fn main() {
    TermLogger::init(
        LevelFilter::Debug,
        Config::default(),
        TerminalMode::Mixed,
        ColorChoice::Auto,
    ).unwrap();
    // ...
}

Next Steps

D-Bus Architecture – understand the communication layer
Troubleshooting – common issues and fixes

nmrs Documentation