Tweak output of __nix_make_gcroot

Dependencies

• [2] 2IS7OERZ Put gcroots in own directory first
• [3] U6EHWR7Y Tweak --gcroots
• [4] WNFTZY3M Optionally prevent relevant nix store paths from being GC'ed
• [5] FYBNOJLT Automagically add --rebuild to nix build commands in interactive mode
• [*] W2G433QU Refactor libdemo and flakeref for nix run commands

Change contents

• replacement in bash/nix-container-demo-helper.sh at line 41
  [2.209]→[3.106:158](∅→∅),[3.106]→[3.106:158](∅→∅)
  − echo "Preventing GC for '${storepath}'"
  [2.209]

  [2.210]
  + if __libdemo_use_colour; then

  + echo -e "\e[0;37mPreventing GC for '${storepath}'\e[0m"

  + else

  + echo "Preventing GC for '${storepath}'"

  + fi
• edit in bash/nix-container-demo-helper.sh at line 62
  [3.1432]→[3.1432:1474](∅→∅)
  − echo "Removing existing GC roots"
• edit in bash/nix-container-demo-helper.sh at line 63
  [3.1502]

  [2.776]
  + echo "Removing existing GC roots"