Remove cross from build tools (#540)

By including a linker for windows and the corresponding toolchain, we
can cross compile to Windows quite easily, and then we no longer
need cross or Docker in Docker.

(Hopefully) closes #530

build/Makefile

@@ -30,7 +30,6 @@ package_version := $(shell grep version -m 1 $(project_path)/Cargo.toml | awk '{
 
 common_rust_args := -v $(project_path):/workspace -w /workspace \
 					-v $(CARGO_HOME)/registry:/usr/local/cargo/registry
-docker_in_docker := -v /var/run/docker.sock:/var/run/docker.sock
 
 #   _____                    _
 #  |_   _|_ _ _ __ __ _  ___| |_ ___
@@ -91,17 +90,17 @@ binary-archive: ensure-build-image build-all-binaries
 
 # Build release and debug binaries for x86_64-unknown-linux-gnu
 build-linux-binary: ensure-build-image
-	docker run --rm $(common_rust_args) $(docker_in_docker) \
- 		--entrypoint=cross $(BUILD_IMAGE_TAG) build --target x86_64-unknown-linux-gnu
-	docker run --rm $(common_rust_args) $(docker_in_docker) \
- 		--entrypoint=cross $(BUILD_IMAGE_TAG) build --target x86_64-unknown-linux-gnu --release
+	docker run --rm $(common_rust_args) \
+ 		--entrypoint=cargo $(BUILD_IMAGE_TAG) build --target x86_64-unknown-linux-gnu
+	docker run --rm $(common_rust_args) \
+ 		--entrypoint=cargo $(BUILD_IMAGE_TAG) build --target x86_64-unknown-linux-gnu --release
 
 # Build release and debug binaries for x86_64-pc-windows-gnu
 build-windows-binary: ensure-build-image
-	docker run --rm $(common_rust_args) $(docker_in_docker) \
- 		--entrypoint=cross $(BUILD_IMAGE_TAG) build --target x86_64-pc-windows-gnu
-	docker run --rm $(common_rust_args) $(docker_in_docker) \
- 		--entrypoint=cross $(BUILD_IMAGE_TAG) build --target x86_64-pc-windows-gnu --release
+	docker run --rm $(common_rust_args) \
+ 		--entrypoint=cargo $(BUILD_IMAGE_TAG) build --target x86_64-pc-windows-gnu
+	docker run --rm $(common_rust_args) \
+ 		--entrypoint=cargo $(BUILD_IMAGE_TAG) build --target x86_64-pc-windows-gnu --release
 
 # Build release and debug binaries for x86_64-apple-darwin
 build-macos-binary:

build/build-image/Dockerfile

@@ -26,7 +26,7 @@ ENV RUSTUP_HOME=/usr/local/rustup \
 # Install packages
 RUN set -eux && \
     apt-get update && \
-    apt-get install -y jq wget zip build-essential libssl-dev pkg-config python3-pip && \
+    apt-get install -y jq wget zip build-essential libssl-dev pkg-config python3-pip g++-mingw-w64-x86-64 && \
     pip3 install live-server
 
 # Install htmltest
@@ -41,10 +41,10 @@ RUN wget https://static.rust-lang.org/rustup/dist/x86_64-unknown-linux-gnu/rustu
     rm rustup-init && \
     chmod -R a+w $RUSTUP_HOME $CARGO_HOME && \
     rustup component add rustfmt clippy && \
-    cargo install cross cargo-watch mdbook && \
+    rustup target add x86_64-pc-windows-gnu && \
+    cargo install cargo-watch mdbook && \
     cargo install cargo-about && \
     cargo install --locked cargo-deny && \
     rustup --version && \
     cargo --version && \
-    rustc --version && \
-    cross --version
+    rustc --version