Try setting NO_CACHE=1 in your variables and deploy.

buildkit cache error still persists

The error is happening because it cannot find the file nginx.staging.conf in your build context. Make sure the file exists in your repo, and isn't ignored by .dockerignore or .gitignore. It could be an incorrect path to the file as well.

The COPY path is now correct (./nginx.staging.conf)

The error still happens at cache validation — buildkit can't compute the checksum

This is not a file-exists or .gitignore problem

Railway needs to clear the buildkit cache on their infrastructure

There is no difference between COPY ./nginx.staging.conf and COPY nginx.staging.conf. The issue is most likely not cache, but what the error says (it just can't find the file in your build context). Can you confirm that the build succeeds locally? It's also worth checking if you have a root directory set in your service settings that might be messing up the build context.

Try disable the build cache yourself, add NO_CACHE=1 to the Service Variables, If it works, you can enable the cache again by removing the Variable

Deployment ID: c9bfb33f-5eb6-405c-8735-cbc24b1fe3ff

Error: "failed to calculate checksum of ref" for nginx.staging.conf

Statement: "This is a buildkit infrastructure issue. The builder instance (builder-xssjno) has a corrupted cache that needs to be cleared. This persists across multiple commits and rebuild attempts."

Also this

I get a message that the build team can resolve this but I have yet been able to reach a build team member

The NO_CACHE=1 variable setting does not work for me

Try selecting the service, press Cmd/Ctrl + K, then redeploy latest commit or redeploy source image.