Shaved 600mB off resulting Docker image
By removing the build files after the build is complete, we save 600mB of unnecessary bulk.  The total image size will now be 1gB.
@@ -22,11 +22,10 @@ RUN apt-get update && apt-get install -y \
wget \
ca-certificates \
libpixman-1-dev \
- && rm -fr /var/lib/apt/lists/*
-RUN mkdir /app
-WORKDIR /app
-COPY . .
+ && rm -rf /var/lib/apt/lists/*
ARG CC=gcc-9
ARG CXX=g++-9
ARG LLVM_CONFIG=llvm-config-9
-RUN make clean && make distrib && make install
+COPY . /app
+RUN cd /app && make clean && make distrib && \
+ make install && cd .. && rm -rf /app
