## TL;DR

Issue grafana/grafana#61524 (closed, 34 comments): What happened: After following the blog about update regarding CircleCI security updates we are seeing GPG error for verifying apt.grafana.com Err:4 mount the host path https at container path //apt.grafana.com stable InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6 Reading package lists...

## Steps

1. Issue grafana/grafana#61524 (closed, 34 comments): **What happened**: After following the blog about update regarding CircleCI security updates we are seeing GPG error for verifying apt.grafana.com

2. Err:4 mount the host path https at container path //apt.grafana.com stable InRelease
 The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6
Reading package lists... Done
W: GPG error: mount the host path https at container path //apt.grafana.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6
E: The repository 'https://apt.grafana.com stable InRelease' is not...

3. A GPG NO_PUBKEY error on apt.grafana.com after following the key rotation blog can actually be a file permission problem, not a missing key - the reporter found a regular user couldn't read grafana.gpg inside /etc/apt/keyrings even though the directory looked readable. Fix: rename the keyrings directory, recreate it, and move grafana.gpg back in, then apt update again.

## When to use

You are seeing this: A GPG NO_PUBKEY error on apt.grafana.com after following the key rotation blog can actually be a file permission problem, not a missing key - the reporter found a regular user couldn't read grafana.gpg inside /etc/apt/keyrings even though the directory... Use this skill when you run into "Public key failure".

## When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

## Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

## Why this happens

Verifying apt.grafana.com Err:4 mount the host path https at container path //apt.grafana.com stable InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9E439B102CF3C0C6 Reading package lists...

## Sources

- https://apt.grafana.com