fix: src in registry should not be cached

Author: kristof-mattei

Dockerfile

@@ -54,12 +54,14 @@ COPY ./.cargo ./Cargo.toml ./Cargo.lock ./
 # both target platforms. It doesn't matter, as after unlocking the other one
 # just validates, but doesn't need to download anything
 RUN --mount=type=cache,id=cargo-git,target=/usr/local/cargo/git/db,sharing=locked \
-    --mount=type=cache,id=cargo-registry,target=/usr/local/cargo/registry,sharing=locked \
+    --mount=type=cache,id=cargo-registry-index,target=/usr/local/cargo/registry/index \
+    --mount=type=cache,id=cargo-registry-cache,target=/usr/local/cargo/registry/cache \
     cargo fetch
 
 RUN --mount=type=cache,target=/build/target/${TARGET},sharing=locked \
     --mount=type=cache,id=cargo-git,target=/usr/local/cargo/git/db \
-    --mount=type=cache,id=cargo-registry,target=/usr/local/cargo/registry \
+    --mount=type=cache,id=cargo-registry-index,target=/usr/local/cargo/registry/index \
+    --mount=type=cache,id=cargo-registry-cache,target=/usr/local/cargo/registry/cache \
     /build-scripts/build.sh build --release --target ${TARGET} --target-dir ./target/${TARGET}
 
 # Rust full build
@@ -76,7 +78,8 @@ RUN touch ./src/main.rs
 # --release not needed, it is implied with install
 RUN --mount=type=cache,target=/build/target/${TARGET},sharing=locked \
     --mount=type=cache,id=cargo-git,target=/usr/local/cargo/git/db \
-    --mount=type=cache,id=cargo-registry,target=/usr/local/cargo/registry \
+    --mount=type=cache,id=cargo-registry-index,target=/usr/local/cargo/registry/index \
+    --mount=type=cache,id=cargo-registry-cache,target=/usr/local/cargo/registry/cache \
     /build-scripts/build.sh install --path . --locked --target ${TARGET} --target-dir ./target/${TARGET} --root /output
 
 # Container user setup