texlive.withPackages: pass package set to requiredTeXPackages instead of empty list

        keySet = p: {

          key = ((p.name or "${p.pname}-${p.version}") + "-" + p.tlOutputName or p.outputName or "");

          inherit p;

          tlDeps = if p ? tlDeps then ensurePkgSets p.tlDeps else (p.requiredTeXPackages or (_: [ ]) [ ]);

          tlDeps = if p ? tlDeps then ensurePkgSets p.tlDeps else (p.requiredTeXPackages or (_: [ ]) tl);

        };

      in

      # texlive.combine: the wrapper already resolves all dependencies