nikivdev/code · error · anyhow::Error

Route already exists: {} -> {}. Use --replace to update.

Error message

Route already exists: {} -> {}. Use --replace to update.

What it means

run_add adds a host->target route to the local domains proxy config. If the host already maps to a different target and --replace was not passed, the command refuses to silently overwrite the existing mapping and bails with this message.

Source

Thrown at src/domains.rs:189

        println!("http://{host}");
    }
    Ok(())
}

fn run_add(paths: &DomainsPaths, opts: DomainsAddOpts, engine: DomainsEngine) -> Result<()> {
    ensure_layout(paths)?;
    let host = normalize_host(&opts.host)?;
    let target = normalize_target(&opts.target)?;

    let mut routes = load_routes(paths)?;
    if let Some(existing) = routes.get(&host) {
        if existing == &target {
            println!("Route already exists: {host} -> {target}");
            maybe_reload_running_proxy(paths, engine)?;
            return Ok(());
        }
        if !opts.replace {
            bail!(
                "Route already exists: {} -> {}. Use --replace to update.",
                host,
                existing
            );
        }
    }

    routes.insert(host.clone(), target.clone());
    save_routes(paths, &routes)?;
    write_route_files(paths, &routes)?;
    maybe_reload_running_proxy(paths, engine)?;
    println!("Added route: {host} -> {target}");
    Ok(())
}

fn run_rm(paths: &DomainsPaths, opts: DomainsRmOpts, engine: DomainsEngine) -> Result<()> {
    ensure_layout(paths)?;
    let host = normalize_host(&opts.host)?;

View on GitHub (pinned to a747e741ae)

Solutions

1. Re-run with --replace to intentionally overwrite the existing route
2. Remove the old route first with the rm subcommand, then add the new one
3. Inspect the current routes (get/list) to confirm the existing target is stale

Example fix

// before
f domains add app.localhost :5173
// error: Route already exists: app.localhost -> :3000. Use --replace to update.
// after
f domains add app.localhost :5173 --replace

let routes = load_routes(&paths)?;
let host = normalize_host(&opts.host)?;
if let Some(existing) = routes.get(&host) {
    if existing != &opts.target && !opts.replace {
        eprintln!("Route exists: {host} -> {existing}; pass --replace to overwrite");
    }
}

match result {
    Err(e) if e.to_string().starts_with("Route already exists:") => {
        eprintln!("Re-run with --replace to update the existing route.");
    }
    other => other?,
}

When it happens

Trigger: `domains add <host> <target>` (or `f domains add`) where the routes file already contains the host pointing to a different target and opts.replace is false.

Common situations: Re-pointing a dev hostname to a new port/service, running an add script twice with a changed target, or forgetting that the route file persisted from a previous session.

Related errors

• Session name '{}' already exists. Use a different name or re
• Refusing to overwrite {}
• Route not found: {}
• Host is empty
• Host must be a hostname like linsa.localhost

AI-assisted analysis of nikivdev/code@a747e741ae (2026-09-01). Data as JSON: /api/errors/2ca32721bd2938ad. Report an issue: GitHub.