anchor.diff:    checkMeta = meta: if shouldCheckMeta then lib.remove null (lib.mapAttrsToList checkMetaAttr meta) else [];
   
     checkPlatform = attrs:
  -    lib.any (lib.meta.platformMatch hostPlatform) attrs.meta.platforms;
  +    (!(attrs ? meta.platforms) || lib.any (lib.meta.platformMatch hostPlatform) attrs.meta.platforms) &&
  +    (!(attrs ? meta.badPlatforms && lib.any (lib.meta.platformMatch hostPlatform) attrs.meta.badPlatforms));
   
     # Check if a derivation is valid, that is whether it passes checks for
     # e.g brokenness or license.
  
positive.code:     isFcitxEngine = bool;
      isIbusEngine = bool;
      isGutenprint = bool;
    };
  
    checkMetaAttr = k: v:
  
negative.code:       { valid = false; reason = "blacklisted"; errormsg = "has a blacklisted license (‘${showLicense attrs.meta.license}’)"; }
      else if !allowBroken && attrs.meta.broken or false then
        { valid = false; reason = "broken"; errormsg = "is marked as broken"; }
      else if !allowUnsupportedSystem && !allowBroken && !(checkPlatform attrs) then
        { valid = false; reason = "broken"; errormsg = "is not supported on ‘${hostPlatform.config}’"; }
      else if !(hasAllowedInsecure attrs) then
        { valid = false; reason = "insecure"; errormsg = "is marked as insecure"; }
  