Use sparse registry for crates.io to speed up builds

Dockerfile.arm64

@@ -1,5 +1,7 @@
 FROM docker.io/rust:bullseye
 
+ENV CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse
+
 RUN apt-get update && apt-get upgrade -y
 RUN apt-get install -y g++-arm-linux-gnueabihf libc6-dev-armhf-cross
 # Uncomment if you need to add more build dependencies to the image:

Dockerfile.armhf

@@ -1,5 +1,7 @@
 FROM docker.io/rust:bullseye
 
+ENV CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse
+
 RUN apt-get update && apt-get upgrade -y
 RUN apt-get install -y g++-aarch64-linux-gnu libc6-dev-arm64-cross
 # Uncomment if you need to add more build dependencies to the image:

Dockerfile.i686

@@ -1,5 +1,7 @@
 FROM docker.io/rust:bullseye
 
+ENV CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse
+
 RUN apt-get update && apt-get upgrade -y
 # Uncomment if you need to add more build dependencies to the image:
 # RUN apt-get install -y <build-depend..>