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In productionProbeginnerLinux permissions

The serial port denies access

Allow the robot service to open its controller without running it as root.

Pairs with Linux evidence toolkit in Robotics Development Setup & Recovery. Read the concept first, then diagnose it here.

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Operator report

`open(/dev/ttyUSB0)` returns permission denied for the service user.

Ubuntu 24.04 setup emulator, isolated disk images, Linux recovery shell, ROS 2 Jazzy

01

System boundary

Trace only the relevant path.

3 nodes
  1. 01udev device node→
  2. 02Unix group permissions→
  3. 03robot serviceOUT
02

How this lab works

You diagnose it. No command list.

Open the repair workspace and gather your own evidence in a real terminal. No diagnostic commands are handed to you - finding the fault is the exercise. Stuck? Progressive hints unlock inside the workspace.

03

Verification

Pass more than the visible symptom.

4 checks
  • Service opens device
  • Service does not run as root
  • Hidden regression behavior
  • Root cause explanation