Raspberry Pi – failed to open vchiq instance [Solved]

I’ve been working on my timelapse camera setup with my raspberry pi and when trying to run my python script I got the following error.

* failed to open vchiq instance

This is a permissions error because I had created a new user that wasn’t in the video group.

All you have to do is make sure that your new user is added to the video group. My username is timepi so I had to run the following command.

Update from Chris’ comment below:

usermod -G video timepi

usermod -a -G video timepi

This allows the timepi user to useย the video camera device and it should all be working now.

Update: Don’t forget to log out and log back in for good measure.

14 thoughts on “Raspberry Pi – failed to open vchiq instance [Solved]”

  1. I tried the usermod -G command on my Pi 2 running Ubuntu Mate as the sole admin user. Unfortunately that command removes the user from the sudo group. This effectively bricked the system because I had just rebooted from a kernel update and had not yet installed the custom wifi driver, which requires sudo. With no recovery mode, I am forced to reinstall the entire OS. ๐Ÿ™ This tragedy could have been prevented by using usermod -a -G instead – and by having a backup admin user, apparently.

    1. Hi Chris,

      Apologies for that I’ve updated the article to reflect your suggestion and yes you should be able to mount the sdcard on another system to update the sudoers.


      1. Great! This may spare some future grief! And I was able to easily edit the /etc/group file from my Ubuntu netbook and restore sudo. I feel bad for another user who made my same mistake but didn’t think of mounting the sdcard externally and had to reinstall Ubuntu Mate.

    1. If you run the script through a php file, which user do you have to give privileges to when you run it over the internet? I tried with pi, but to no avail. Were you running the php code locally?

  2. What if that file just doesn’t exist on the device? Is there a way to configure it to work with the PCDuino2?

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