message: rewrite Dockerfile to avoid kaniko bug
  see
diff: @@ -11,21 +11,21 @@ ENV RUSTUP_HOME=/usr/local/rustup \
  RUN set -eux; \
  dpkgArch="$(dpkg --print-architecture)"; \
  - case "${dpkgArch##*-}" in \
  + case "$dpkgArch##*-" in \
  amd64) rustArch='x86_64-unknown-linux-gnu'; rustupSha256='3dc5ef50861ee18657f9db2eeb7392f9c2a6c95c90ab41e45ab4ca71476b4338' ;; \
  armhf) rustArch='armv7-unknown-linux-gnueabihf'; rustupSha256='67777ac3bc17277102f2ed73fd5f14c51f4ca5963adadf7f174adf4ebc38747b' ;; \
  arm64) rustArch='aarch64-unknown-linux-gnu'; rustupSha256='32a1532f7cef072a667bac53f1a5542c99666c4071af0c9549795bbdb2069ec1' ;; \
  i386) rustArch='i686-unknown-linux-gnu'; rustupSha256='e50d1deb99048bc5782a0200aa33e4eea70747d49dffdc9d06812fd22a372515' ;; \
  - *) echo >&2 "unsupported architecture: ${dpkgArch}"; exit 1 ;; \
  + *) echo >&2 "unsupported architecture: $dpkgArch"; exit 1 ;; \
  esac; \
  - url="https://static.rust-lang.org/rustup/archive/1.24.3/${rustArch}/rustup-init"; \
  + url="https://static.rust-lang.org/rustup/archive/1.24.3/$rustArch/rustup-init"; \
  wget "$url"; \
  - echo "${rustupSha256} *rustup-init" | sha256sum -c -; \
  + echo "$rustupSha256 *rustup-init" | sha256sum -c -; \
  chmod +x rustup-init; \
  ./rustup-init -y --no-modify-path \
  --profile minimal \
  --default-toolchain $RUST_VERSION \
  - --default-host ${rustArch} \
  + --default-host $rustArch \
  --component $RUST_COMPONENTS \
  --target $RUST_TARGETS \
  ; \
  