message: Relax package naming for Ubuntu 18.04 Dockerfile.
  The package version pinning seems to be a bad idea for development
  Dockerfile. It does make sense for release Dockerfiles, though.
  This commit relaxes some package versions to make the Dockerfile
  work again, more general solution needs to be applied to all Dockerfiles
  we have.
diff: @@ -15,8 +15,8 @@ ARG EXTRA_BUILD_ARG
  RUN uname -a
  # Packages required to build ISPC and Clang.
  -RUN apt-get -y update && apt-get --no-install-recommends install -y wget=1.19.4-1ubuntu2.2 build-essential=12.4ubuntu1 gcc=4:7.4.0-1ubuntu2.3 \
  - g++=4:7.4.0-1ubuntu2.3 git=1:2.17.1-1ubuntu0.13 python3-dev=3.6.7-1~18.04 libncurses5-dev=6.1-1ubuntu1.18.04 libtinfo-dev=6.1-1ubuntu1.18.04 ca-certificates=20211016~18.04.1 && \
  +RUN apt-get -y update && apt-get --no-install-recommends install -y wget=1.19.4-1ubuntu* build-essential=12.4ubuntu* gcc=4:7.4.0-1ubuntu* \
  + g++=4:7.4.0-1ubuntu* git=1:2.17.1-1ubuntu* python3-dev=3.6.7-1~18.04 libncurses5-dev=6.1-1ubuntu* libtinfo-dev=6.1-1ubuntu* ca-certificates && \
  rm -rf /var/lib/apt/lists/*
  # Download and install required version of cmake (3.14 for x86, 3.20 for aarch64, as earlier versions are not available as binary distribution) for ISPC build
  @@ -67,10 +67,10 @@ ARG LLVM_VERSION
  # ISPC builds in C++17 mode and will fail without modern libstdc++
  # Also install regular ISPC dependencies
  -RUN if [[ $(uname -m) =~ "x86" ]]; then export CROSS_LIBS="libc6-dev-i386=2.27-3ubuntu1.6"; else export CROSS_LIBS="libc6-dev-armhf-cross=2.27-3ubuntu1cross1.1"; fi && \
  +RUN if [[ $(uname -m) =~ "x86" ]]; then export CROSS_LIBS="libc6-dev-i386=2.27-3ubuntu*"; else export CROSS_LIBS="libc6-dev-armhf-cross=2.27-3ubuntu*"; fi && \
  apt-get -y update && apt-get --no-install-recommends install -y software-properties-common=0.96.24.32.18 && \
  add-apt-repository ppa:ubuntu-toolchain-r/test -y && apt-get -y update && \
  - apt-get --no-install-recommends install -y libstdc++-9-dev=9.4.0-1ubuntu1~18.04 && \
  + apt-get --no-install-recommends install -y libstdc++-9-dev=9.4.0-1ubuntu* && \
  apt-get --no-install-recommends install -y m4=1.4.18-1 bison=2:3.0.4.dfsg-1build1 flex=2.6.4-6 $CROSS_LIBS && \
  rm -rf /var/lib/apt/lists/*
  