There is no event listener available for automatic restart in watch mode, try using `launchBus`, it only works on first launch

What's going wrong?

There is no event listener available for automatic restart in watch mode, try using launchBus, it only works on first launch

How could we reproduce this issue?

I tried re-running the following code using my own bun+yargs CLI

bun --bun src/console/bin.ts

export const startPM2 = async (
    configure: Configure,
    args: Arguments<StartCommandArguments>,
    config: CLIConfig,
) => {
    const { name } = await configure.get<AppConfig>('app');
    const script = args.typescript ? config.paths.ts : config.paths.js;
    const pm2Config = await getPm2Config(
        configure,
        {
            command: 'start',
            ...pick(args, ['watch', 'typescript']),
        },
        config,
        script,
    );
    const connectCallback = (error?: any) => {
        if (!isNil(error)) {
            console.error(error);
            process.exit(2);
        }
    };
    const startCallback = (error?: any) => {
        if (!isNil(error)) {
            console.error(error);
            exit(1);
        }
        pm2.disconnect();
    };
    const restartCallback = (error?: any) => {
        if (!isNil(error)) {
            pm2.start(pm2Config, (serr) => startCallback(serr));
        } else {
            pm2.disconnect();
        }
    };

    pm2.connect((cerr) => {
        connectCallback(cerr);
        args.force ? pm2.restart(name, restartCallback) : pm2.reload(name, restartCallback);
    });
    // eslint-disable-next-line func-names
    pm2.launchBus(function (err, bus) {
        // eslint-disable-next-line func-names
        bus.on('process:event', function (data: any) {
            console.log(data.event)
            // generateSwaggerMetadata(config, false);
        });
    });
};

On the first start, working fine

But using pm2 restart or automatic restart through watch is invalid.

Supporting information

$ pm2 report

Start at src/console/bin.ts and inspect the pm2.connect, pm2.launchBus, and process:event flow shown in the report. Reproduce the initial start followed by pm2 restart or a watch-triggered restart with the Bun command; done means the event listener remains available and reports events after subsequent launches.