anchor.diff:  
   COPY swift-all-keys.asc .
   RUN set -e; \
  -    SWIFT_WEBDIR="$SWIFT_WEBROOT/$SWIFT_BRANCH/$(echo $SWIFT_PLATFORM | tr -d .)/" \
  +    SWIFT_WEBDIR="$SWIFT_WEBROOT/$SWIFT_BRANCH/$(echo $SWIFT_PLATFORM | tr -d .)" \
       && SWIFT_BIN_URL="$SWIFT_WEBDIR/$SWIFT_VERSION/$SWIFT_VERSION-$SWIFT_PLATFORM.tar.gz" \
       && SWIFT_SIG_URL="$SWIFT_BIN_URL.sig" \
       # - Grab curl here so we cache better up above
  
positive.code: ARG SWIFT_PLATFORM=ubuntu18.04
  ARG SWIFT_BRANCH=swift-5.3.3-release
  ARG SWIFT_VERSION=swift-5.3.3-RELEASE
  ARG SWIFT_WEBROOT=https://swift.org/builds/
  
  ENV SWIFT_SIGNING_KEY=$SWIFT_SIGNING_KEY \
      SWIFT_PLATFORM=$SWIFT_PLATFORM \
  
negative.code: 	    --ignore-installed requests --ignore-installed chardet \
  	    --ignore-installed urllib3 \
  	    --upgrade setuptools && \
      pip install --no-cache-dir -Iv conan==1.11.2 && \
      conan config install https://github.com/conan-io/conanclientcert.git
  
  
  # install NuGet (w. mono)
  # https://docs.microsoft.com/en-us/nuget/install-nuget-client-tools#macoslinux
  