q&a.md

Q&A

• Why npm ci reports npm ERR! command sh -c node-pre-gyp install --fallback-to-build...

  • 

  • Answer

    • The dependencies of node-canvas may be forgotten to install, please refer to This docs

• Why npm ci reports ETIMEOUT 20.205.243.166:443

  • 

  • Answer

    • The reasons caused by the network. You can retry or use VPN.

• Why Mineflayer reports THREE.WebGLRenderer: Cannot read properties of null...

  • 
  • Answer
    • You probably run MineLand in a headless machine.
    • Refer to This guide, you needs to install Xvfb and Mesa.
    • A simple method to fix is 1.8 Headless machine.

• Why MineLand reports RuntimeWarning: Couldn't find ffmpeg or avconv...

  • 
  • Answer
    • MineLand provides Audio Information in observation space.
    • If you want to enable Sound System and let agents to deal with sounds, ffmpeg needs to be installed. Then, add enable_sound_system = True in mineland.make()
    • Or, you can ignore this info.

• Why server reports Netty Server IO ERROR, Thread dumps

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  • In fact, the cause of this problem is unknown. This may be related to personal computer configuration.
  • Answer
    • Restart MineLand to try again.

• Why server reports There is insufficient memory for the JRE to continue.

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  • Answer
    • You need to upgrade your machine or

• Why mineflayer reports `Type Error: Cannot read properties of undefined (reading 'yaw')

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  • Answer

    • The bot has not been fully initialized yet.

    • You can increase the initialization duration in app.post("/start"...) of ./mineland/sim/mineflayer/index.js.

    • setTimeout(() => {
          obs = []
          for(let i = 0; i < number_of_bot; i++) {
              obs.push(bot_manager.getBotObservation(i));
          }
          res.status(200).json({
              return_code: 200,
              observation: obs,
          })
      }, 20000) // wait for 20 seconds to make sure all bots are spawned
      // You can change 20000 to 30000 to avoid this problem