GPG errors during deployment are usually caused by outdated or expired package signing keys in your build environment. To help narrow it down can you share the full error from your deploy logs? Specifically the line that shows the GPG error.

In the meantime, a few common fixes:

If you're using a apt-get command in your Dockerfile or nixpacks config, add apt-get update before it

If it's a Node/Python project with no custom Dockerfile, try adding a nixpacks.toml that forces a fresh build cache

Go to your service > Deployments > three dots on latest deploy > "Clear build cache" then redeploy

Mate the cache clear fix resolves this 90% of the time on Railway.

Can you paste the exact GPG error line from the build logs? The fix depends on whether it is NO_PUBKEY, EXPKEYSIG, BADSIG, or an invalid signature from a specific third-party apt repo.

A few useful distinctions:

• If this is from your own Dockerfile, the fix belongs in the Dockerfile: run apt-get update immediately before apt-get install, and update the affected repository key using the repo’s current signed-by=/usr/share/keyrings/... instructions.
• If this is from a third-party repo such as Google Chrome, NodeSource, PostgreSQL, MongoDB, MySQL, etc., clearing Railway cache alone may not fix it. The repo signing key may have expired and needs to be refreshed.
• If you are not using a Dockerfile and Railway is building with Railpack, then clear build cache and redeploy is a reasonable first test, because Railway’s build docs say Railpack handles the generated image/build layers.

If you share the exact GPG line, the important parts are the repo URL and key/error type. That will tell whether this is a stale build cache, expired third-party apt key, or a broken apt source.

Railway build docs:

https://docs.railway.com/builds/build-configuration

https://docs.railway.com/builds/nixpacks