why can't I run an nextjs project with the pm2 in the bun with the config file here below?

[BertramYe]

hello guys, have anyone tried with the bun to develop an nextjs project, and use the pm2 to host the project?

but why when I use the ecosystem.config.js here below, why it can't run ?

# enviroments

os: windows 10

nextjs: 16.1.1

bun: 1.3.5

pm2: 6.0.14

but when I run the commend below here with the config file here below,
it can be run normally, but tested it with the address : http://localhost:3000/, for which it dosen't work.

$ pm2 start ecosystem.config.js --env production

// ecosystem.config.js

module.exports = {
  apps: [{

    name: 'blog',


    interpreter: 'bun', 
    interpreter_args: '',


    // script
    script: 'bun',
    args: 'run start', 
    cwd: './',
    
    instances: 1,
    exec_mode: 'fork', 
    
    autorestart: true,
    restart_delay: 3000,
    max_restarts: 10,
    
    // moniter
    watch: true, 
    ignore_watch: [
      'node_modules',
      '.next',
      'logs',
      '*.log',
      '*.tmp'
    ],
    
    // memory
    max_memory_restart: '800M',
    
    // logs
    log_date_format: 'YYYY-MM-DD HH:mm:ss',
    error_file: './logs/error.log',
    out_file: './logs/output.log',
    pid_file: './logs/nextjs.pid',
    
    // enviroment
    env: {
      NODE_ENV: 'development',
      PORT: 3000,
      HOST: '0.0.0.0',
      BUN_ENV: 'development',
      NEXT_TELEMETRY_DISABLED: '1',
    },
    
    env_production: {
      // NODE_ENV: 'production',
      PORT: 3000,
      HOST: '0.0.0.0',
      BUN_ENV: 'production',
  
      NEXT_SERVER_ACTIONS: '1',
      NEXT_TELEMETRY_DISABLED: '1',
      // Bun optimised
      BUN_JSC_useJIT: true,
      BUN_JSC_useDFGJIT: true,
      BUN_JSC_useFTLJIT: true,
    },
    
    env_staging: {
      NODE_ENV: 'staging',
      PORT: 3001,
      HOST: '0.0.0.0',
      BUN_ENV: 'staging',
    }
  }]
};

but when I tried with the commend here below, I found that it works for the page: http://localhost:3000/,
also I have checked the logs file content (./logs/error.log and ./logs/output.log), and found there were not any error logs shows in there,
how can I do to make it works?

[sunnypatell]

@BertramYe the problem is in your ecosystem.config.js. you have interpreter: 'bun' AND script: 'bun', so pm2 executes bun bun run start -- double invocation. pm2's interpreter field tells it which binary runs the script, so setting both to bun is redundant and broken.

fix (pick one):

option A -- bun as interpreter, next as script:

module.exports = {
  apps: [{
    name: 'blog',
    interpreter: 'bun',
    script: 'node_modules/.bin/next',
    args: 'start',
    exec_mode: 'fork',
    env_production: {
      NODE_ENV: 'production',   // <-- you have this commented out, uncomment it
      PORT: 3000,
    },
  }]
};

option B -- bun as script, no interpreter:

module.exports = {
  apps: [{
    name: 'blog',
    interpreter: 'none',
    script: 'bun',
    args: '--bun run start',
    exec_mode: 'fork',
    env_production: {
      NODE_ENV: 'production',
      PORT: 3000,
    },
  }]
};

also: your env_production block has NODE_ENV: 'production' commented out. next.js needs that to run in production mode. uncomment it and start with pm2 start ecosystem.config.js --env production.

the pm2 ecosystem docs explain the interpreter/script relationship. and the BUN_JSC_useJIT flags you're setting are already enabled by default in bun, so those lines are harmless but unnecessary.

[ra-sun-god]

There is now a native process manager built specifically for the Bun runtime. It provides feature parity with PM2 and is designed to work seamlessly with existing PM2 ecosystem configuration file, no changes required.

You can explore it here: bun-bm2/bm2

Your existing ecosystem file works as-is:

// ecosystem.config.js

export default {
  apps: [{
    name: 'blog',
    script: '/path/to/your/app/start.ts',

    instances: 1,
    exec_mode: 'cluster', 
    
    autorestart: true,
    restart_delay: 3000,
    max_restarts: 10,
    
    // monitor
    watch: true, 
    ignore_watch: [
      'node_modules',
      '.next',
      'logs',
      '*.log',
      '*.tmp'
    ],
    
    // memory
    max_memory_restart: '800M',
    
    // logs
    log_date_format: 'YYYY-MM-DD HH:mm:ss',
    error_file: './logs/error.log',
    out_file: './logs/output.log',
    pid_file: './logs/nextjs.pid',
    
    // environment
    env: {
      NODE_ENV: 'development',
      PORT: 3000,
      HOST: '0.0.0.0',
      BUN_ENV: 'development',
      NEXT_TELEMETRY_DISABLED: '1',
    },
    
    env_production: {
      PORT: 3000,
      HOST: '0.0.0.0',
      BUN_ENV: 'production',
  
      NEXT_SERVER_ACTIONS: '1',
      NEXT_TELEMETRY_DISABLED: '1',

      // Bun-optimized flags
      BUN_JSC_useJIT: true,
      BUN_JSC_useDFGJIT: true,
      BUN_JSC_useFTLJIT: true,
    },
    
    env_staging: {
      NODE_ENV: 'staging',
      PORT: 3001,
      HOST: '0.0.0.0',
      BUN_ENV: 'staging',
    }
  }]
};

One small adjustment: since BM2 is Bun-native, you do not need to define:

interpreter: 'bun',
interpreter_args: ''

BM2 directly uses Bun’s runtime internally, so there’s no need to spawn Bun explicitly.