Update from debian stretch (9) to buster (10) for ghc 8.6, 8.8

Author: AlistairB

8.6/Dockerfile

@@ -1,15 +1,15 @@
-FROM debian:stretch
+FROM debian:buster
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends gnupg ca-certificates dirmngr && \
     rm -rf /var/lib/apt/lists/*
 
 ARG GHC=8.6.5
-ARG STACK=1.9.3
-ARG CABAL_INSTALL=2.4
+ARG STACK=2.1.3
+ARG CABAL_INSTALL=3.0
 
 RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 427CB69AAC9D00F2A43CAF1CBA3CBA3FFE22B574 && \
-    echo 'deb http://downloads.haskell.org/debian stretch main' > /etc/apt/sources.list.d/ghc.list && \
+    echo 'deb http://downloads.haskell.org/debian buster main' > /etc/apt/sources.list.d/ghc.list && \
     apt-get update && \
     apt-get install -y --no-install-recommends \
         cabal-install-${CABAL_INSTALL} \
@@ -28,6 +28,7 @@ RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 427CB69AAC9D00F2A43
 
 RUN export GNUPGHOME="$(mktemp -d)" && \
     gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys C5705533DA4F78D8664B5DC0575159689BEFB442 && \
+    gpg --batch --keyserver ha.pool.sks-keyservers.net --recv-keys 2C6A674E85EE3FB896AFC9B965101FF31C5C154D && \
     curl -fSL https://github.com/commercialhaskell/stack/releases/download/v${STACK}/stack-${STACK}-linux-x86_64.tar.gz -o stack.tar.gz && \
     curl -fSL https://github.com/commercialhaskell/stack/releases/download/v${STACK}/stack-${STACK}-linux-x86_64.tar.gz.asc -o stack.tar.gz.asc && \
     gpg --batch --trusted-key 0x575159689BEFB442 --verify stack.tar.gz.asc stack.tar.gz && \

8.8/Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:stretch
+FROM debian:buster
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends gnupg ca-certificates dirmngr && \
@@ -9,7 +9,7 @@ ARG STACK=2.1.3
 ARG CABAL_INSTALL=3.0
 
 RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 427CB69AAC9D00F2A43CAF1CBA3CBA3FFE22B574 && \
-    echo 'deb http://downloads.haskell.org/debian stretch main' > /etc/apt/sources.list.d/ghc.list && \
+    echo 'deb http://downloads.haskell.org/debian buster main' > /etc/apt/sources.list.d/ghc.list && \
     apt-get update && \
     apt-get install -y --no-install-recommends \
         cabal-install-${CABAL_INSTALL} \