Use the standard Docker build cache

.dockerignore

@@ -1,5 +1,4 @@
 upstream/HubBackend/.git
-.build-cache
 .venv*
 build
 dist

.gitignore

@@ -1,5 +1,4 @@
 .env
-.build-cache/
 config/config.json
 data/*
 !data/.gitignore

README.md

@@ -99,15 +99,11 @@ docker compose up -d
 docker compose ps
 ```
 
-The backend build exports its complete BuildKit cache to
-`.build-cache/backend`. This directory includes the intermediate Nuitka build
-layers. Keep it to reuse the compiled result after Docker removes its internal
-build cache. The directory can be large and is excluded from Git and the Docker
-build context.
-
 The Python builder image is pinned to a tested image digest. Update this digest
 deliberately when the compiler environment needs an update. A runtime base
-image update does not invalidate the Nuitka build layer.
+image update does not invalidate the Nuitka build layer. Docker reuses its
+normal internal build cache. A complete build is necessary after that cache is
+removed.
 
 By default, the API is available at `http://localhost:17777/api`. Swagger UI is
 available at `http://localhost:17777/api/doc`.

compose.yaml

@@ -55,10 +55,6 @@ services:
   backend:
     build:
       context: .
-      cache_from:
-        - type=local,src=.build-cache/backend
-      cache_to:
-        - type=local,dest=.build-cache/backend,mode=max
     restart: unless-stopped
     environment:
       TRUST_HOST_PROXY: "1"