aarch64-linux-deb9, armv7-linux-deb9: Add cabal to PATH

aarch64-linux-deb9/Dockerfile

@@ -54,7 +54,8 @@ ENV CABAL_VERSION 3.0.0.0
 #WORKDIR /Cabal/cabal-install
 #RUN EXTRA_CONFIGURE_OPTS=--disable-optimization ./bootstrap.sh --global --no-doc
 #RUN ls /Cabal/cabal-install/dist/build
-RUN curl http://home.smart-cactus.org/~ben/ghc/cabal-install-3.0.0.0-aarch64-debian9-linux.tar.gz | tar -xzC /usr/local/bin
+RUN curl http://home.smart-cactus.org/~ben/ghc/cabal-install-$CABAL_VERSION-aarch64-debian9-linux.tar.gz | tar -Jx && \
+    mv cabal /usr/local/bin/cabal
 
 ENV PATH /home/ghc/.local/bin:/opt/ghc/$GHC_VERSION/bin:$PATH
 

armv7-linux-deb9/Dockerfile

@@ -48,14 +48,15 @@ RUN curl http://releases.llvm.org/$LLVM_VERSION/clang+llvm-$LLVM_VERSION-armv7a-
     llc --version
 
 # Cabal
-#ENV CABAL_VERSION 3.0.0.0
+ENV CABAL_VERSION 3.0.0.0
 #RUN git clone https://github.com/haskell/Cabal
 #WORKDIR /Cabal
 #RUN git checkout cabal-install-v$CABAL_VERSION
 #WORKDIR /Cabal/cabal-install
 #RUN EXTRA_CONFIGURE_OPTS=--disable-optimization ./bootstrap.sh --global --no-doc
 #RUN ls /Cabal/cabal-install/dist/build
-RUN curl http://home.smart-cactus.org/~ben/ghc/cabal-install-3.0.0.0-armv7l-debian9-linux.tar.gz | tar -xzC /usr/local/bin
+RUN curl http://home.smart-cactus.org/~ben/ghc/cabal-install-$CABAL_VERSION-armv7l-debian9-linux.tar.gz | tar -Jx && \
+    mv cabal /usr/local/bin/cabal
 
 ENV PATH /home/ghc/.local/bin:/opt/ghc/$GHC_VERSION/bin:$PATH