message: Makefile: use cargo absolute path
  In case test has to switch user to root, the test tool still
  can find cargo
diff: @@ -83,6 +83,9 @@ endif
  CARGO_BUILD_GEARS = -v ~/.ssh/id_rsa:/root/.ssh/id_rsa -v ~/.cargo/git:/root/.cargo/git -v ~/.cargo/registry:/root/.cargo/registry
  +CARGO = $(shell which cargo)
  +SUDO = $(shell which sudo)
  +
  docker-static:
  docker build -t nydus-rs-static --build-arg ARCH=${ARCH} misc/musl-static
  docker run --rm ${CARGO_BUILD_GEARS} --workdir /nydus-rs -v ${current_dir}:/nydus-rs nydus-rs-static
  @@ -92,7 +95,7 @@ docker-static:
  smoke: ut
  # No need to involve `clippy check` here as build from target `virtiofs` or `fusedev` always does so.
  # TODO: Put each test function into separated rs file.
  - TEST_WORKDIR_PREFIX=$(TEST_WORKDIR_PREFIX) cargo test --test '*' $(FUSEDEV_COMMON) -- --nocapture --test-threads=8
  + $(SUDO) TEST_WORKDIR_PREFIX=$(TEST_WORKDIR_PREFIX) $(CARGO) test --test '*' $(FUSEDEV_COMMON) -- --nocapture --test-threads=8
  docker-nydus-smoke:
  docker build -t nydus-smoke --build-arg ARCH=${ARCH} misc/nydus-smoke
  