I'm experiencing a persistent issue where Railway continues to use Nixpacks despite having:

  1. A Dockerfile in the repository root

  2. railway.toml with explicit configuration:

  [build]

  builder = "DOCKERFILE"

  dockerfilePath = "Dockerfile"

  3. Environment variable RAILWAY_DOCKERFILE_PATH=./Dockerfile set via Railway CLI

  4. Multiple git pushes with these configurations

Build logs consistently show:

  ==============

  Using Nixpacks

  ==============

  Even though the logs also show [internal] load build definition from Dockerfile, Railway is actually building with Nixpacks (I can see it running nix-env, Nixpacks stages, etc.).

What I've Tried:

  - Removing railway.toml to use UI settings (didn't work)

  - Adding railway.toml back with explicit builder = "DOCKERFILE" (didn't work)

  - Setting RAILWAY_DOCKERFILE_PATH environment variable (didn't work)

  - Multiple code pushes to trigger fresh builds (didn't work)

Question:

  Is there a Railway build cache that locks in the builder decision? How can I force Railway to actually use my Dockerfile instead of Nixpacks? Is there a way to completely reset the build cache or service configuration?