anchor.diff:  } :
   
   assert builtins.elem network [ "ethernet" "infiniband" "omnipath" ];
  -
  -assert
  -  (if network == "infiniband"
  -     then (lib.lists.all (x: x != null) [ infiniband-diags opensm rdma-core ])
  -     else true
  -  );
  -
  -assert
  -  (if network == "omnipath"
  -     then (lib.lists.all (x: x != null) [ libpsm2 libfabric ])
  -     else true
  -  );
   
   let
   
  
positive.code:     slurm
      openssh
      hwloc
      rdma-core
      infiniband-diags
      opensm
      libpsm2
      libfabric
    ];
  
    configureFlags = [
      "--with-pm=hydra"
  
negative.code: 
    nativeBuildInputs = [ pkgconfig bison makeWrapper ];
    propagatedBuildInputs = [ numactl rdma-core zlib infiniband-diags opensm ];
    buildInputs = with lib; [
      numactl
      libxml2
      perl
  