anchor.diff:    handleEvalIssue = { meta, attrs }: { reason , errormsg ? "" }:
       let
         msg = if inHydra
  -        then "Failed to evaluate ${attrs.name or "«name-missing»"}: «${reason}»: ${errormsg}"
  +        then "Failed to evaluate ${getName attrs}: «${reason}»: ${errormsg}"
           else ''
  -          Package ‘${attrs.name or "«name-missing»"}’ in ${pos_str meta} ${errormsg}, refusing to evaluate.
  +          Package ‘${getName attrs}’ in ${pos_str meta} ${errormsg}, refusing to evaluate.
   
           '' + (builtins.getAttr reason remediation) attrs;
   
  
positive.code:       actualOutputs = attrs.outputs or [ "out" ];
        missingOutputs = builtins.filter (output: ! builtins.elem output actualOutputs) expectedOutputs;
      in ''
        The package ${attrs.name} has set meta.outputsToInstall to: ${builtins.concatStringsSep ", " expectedOutputs}
  
        however ${attrs.name} only has the outputs: ${builtins.concatStringsSep ", " actualOutputs}
  
        and is missing the following ouputs:
  
  
negative.code:         You can install it anyway by whitelisting this package, using the
          following methods:
  
          a) for `nixos-rebuild` you can add ‘${getName attrs}’ to
             `nixpkgs.config.permittedInsecurePackages` in the configuration.nix,
             like so:
  
               {
                 nixpkgs.config.permittedInsecurePackages = [
                   "${getName attrs}"
                 ];
               }
  
          b) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
          ‘${getName attrs}’ to `permittedInsecurePackages` in
          ~/.config/nixpkgs/config.nix, like so:
  
               {
                 permittedInsecurePackages = [
                   "${getName attrs}"
                 ];
               }
  
  