Builds failing due to unvailable gpg key

After hiccups on circleci today suddenly all builds are failing even though the circleci status claims that all issues were resolved. We are using machine executor and the builds are failing due gpg error on circleci/trusty source:

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: trusty InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 4E6910DFCB68C9CD

What to do here?

You report is a little vague but are you getting this error when running apt-get update?

If so, you are able to mitigate this issue temporarily by running before apt-get:

wget -q -O - | sudo apt-key add -

I found this answer here, as I have been having the same issue myself:

well that solves the problem only for google source, but not for circleci/trusty source, where you cannot update key

Can you provide a link to your build or provide more information about the issue e.g commands executed and the complete error output?

Been having this issue today.

wget -q -O - | sudo apt-key add -

Fixes the issue for google, but the same for packagecloud still remains.