Add and use demowarning

Dependencies

• [2] 3GPSC2KX Add compatibility checks for fancy parts of the demos
• [3] TEQJC3HX Add 03-nix-container
• [4] ZFMPQAFV Fix and extend cross compilation with static builds
• [5] BH5XPS7C Add 07-vm-integration test
• [*] 7AUC4NKI Initial commit
• [*] EGQ4SEV5 Add demo for 04

Change contents

• edit in libdemo/libdemo.sh at line 113
  [7.1610]

  [7.1610]
  + demowarning() {

  + if [ "${__libdemo_prev_output}" != democmd ]; then

  + echo

  + fi

  + if __libdemo_use_colour; then

  + local -r prefix="\e[1;31m[!]\e[0m"

  + else

  + local -r prefix="[!]"

  + fi

  + echo -e "${prefix}" "$@"

  + __libdemo_prev_output=demowarning

  + }

  +

  + w() {

  + demowarning "$@"

  + }

  +
• replacement in 07-vm-integration-test/demo.sh at line 31
  [2.114]→[2.114:211](∅→∅)
  − n "If /dev/kvm is not world-read-writable VMs will be emulated which is prohibitively slow!"
  [2.114]

  [2.211]
  + w "If /dev/kvm is not world-read-writable VMs will be emulated which is prohibitively slow!"
• replacement in 04-cmake-and-cross/demo.sh at line 52
  [2.350]→[2.350:460](∅→∅)
  − n "It seems aarch64-linux binfmt emulation is not available, the following part of the demo may not work"
  [2.350]

  [2.460]
  + w "It seems aarch64-linux binfmt emulation is not available, the following part of the demo may not work"
• replacement in 03-nix-container/demo.sh at line 22
  [2.576]→[2.576:717](∅→∅)
  − n "No subuid range defined for user, consider running 'sudo usermod --add-subuids 10000-75535 ${USER}' to allow rootless podman to work"
  [2.576]

  [2.717]
  + w "No subuid range defined for user, consider running 'sudo usermod --add-subuids 10000-75535 ${USER}' to allow rootless podman to work"