Cache Rust build artifacts for Alpine packages

README.md

@@ -241,6 +241,13 @@ ALPINE_PACKAGE=greptimedb mise run apk:build
 ALPINE_PACKAGE=greptimedb SKIP_BUILD=1 mise run apk:test-install
 ```
 
+Docker-backed build tasks keep Cargo registry, Rustup, and Cargo target caches in named Docker volumes. The default volume scope is derived from the Git remote owner/repository and is split by package and architecture. Override it when needed:
+
+```sh
+ALPINE_APK_CACHE_SCOPE=public-alpine-packages ALPINE_PACKAGE=greptimedb mise run apk:build
+ALPINE_APK_CACHE_PREFIX=alpine-apk-ci ALPINE_PACKAGE=greptimedb mise run apk:build
+```
+
 Use the test shell to inspect the package in Alpine with the current build
 installed: