anchor.diff:  
   let
     # Grammars we want to fetch from the tree-sitter github orga
  -  knownTreeSitterOrgGrammarRepos = [
  +  knownTreeSitterOrgGrammarRepos = jsonFile "known-tree-sitter-org-grammar-repos" [
       "tree-sitter-javascript"
       "tree-sitter-c"
       "tree-sitter-swift"
  
positive.code:       echo "$res" 1>&2
        exit 1
      fi
      cat "$known"
    '';
  
    # TODO
  
negative.code:   update-all-grammars = writeShellScript "update-all-grammars.sh" ''
      set -euo pipefail
      echo "fetching list of grammars" 1>&2
      treeSitterRepos=$(${latestGithubRepos { orga = "tree-sitter"; }})
      echo "checking the tree-sitter repo list against the grammars we know" 1>&2
      printf '%s' "$treeSitterRepos" | ${checkTreeSitterRepos}
      knownGrammars=$(cat "${knownTreeSitterOrgGrammarRepos}")
      # change the json list into a item-per-line bash format
      grammarNames=$(printf '%s' "$knownGrammars" | ${jq}/bin/jq --raw-output '.[]')
      outputDir="${toString ./.}/grammars"
  