add -u 0 for docker exec and set default toolchain for cargo

Makefile

@@ -12,7 +12,7 @@ ifeq ($(ARCH),x86_64)
 	cd ./awsm/wasmception && wget ${WASMCEPTION_URL} -O wasmception.tar.gz && tar xvfz wasmception.tar.gz && rm wasmception.tar.gz
 endif
 	test -f ./${COMPILER}/wasmception/dist/bin/clang || make -C ${COMPILER}/wasmception
-	@cd ${COMPILER} && cargo build --release && cd ${ROOT}
+	@cd ${COMPILER} && RUSTUP_TOOLCHAIN=stable cargo build --release && cd ${ROOT}
 
 # Sanity check that the aWsm compiler built and is in our PATH
 .PHONY: build-validate

devenv.sh

@@ -103,7 +103,7 @@ envsetup() {
 
 	# Execute the make install command on the sledge-dev image to build the project
 	echo "Building ${SYS_NAME}"
-	docker exec \
+	docker exec -u 0 \
 		--tty \
 		--workdir "${HOST_SYS_MOUNT}" \
 		${SYS_DOC_DEVNAME} make install
@@ -144,7 +144,7 @@ envrun() {
 	fi
 
 	echo "Running shell"
-	docker exec --tty --interactive --workdir "${HOST_SYS_MOUNT}" ${SYS_DOC_NAME} /bin/bash
+	docker exec -u 0 --tty --interactive --workdir "${HOST_SYS_MOUNT}" ${SYS_DOC_NAME} /bin/bash
 }
 
 # Stops and removes the sledge "runtime" container