Fix mpich package

pkgs/index.nix

@@ -24,7 +24,7 @@ let
     #lmbench = callPackage ./lmbench/default.nix { }; # Broken
     mcxx = callPackage ./mcxx/default.nix { };
     mpi = final.mpich; # Set MPICH as default
-    mpich = callPackage ./mpich/default.nix { };
+    mpich = callPackage ./mpich/default.nix { mpich = prev.mpich; };
     nanos6 = callPackage ./nanos6/default.nix { };
     nanos6Debug = final.nanos6.override { enableDebug = true; };
     nixtools = callPackage ./nixtools/default.nix { };

pkgs/mpich/default.nix

@@ -1,8 +1,10 @@
 {
-  mpich
+  lib
+, mpich
 , pmix
 , libfabric
 , gfortran
+, symlinkJoin
 }:
 
 # Configure the OFI network for MPICH
@@ -36,4 +38,4 @@ in mpich.overrideAttrs (old: {
     "FFLAGS=-fallow-argument-mismatch" # https://github.com/pmodels/mpich/issues/4300
     "FCFLAGS=-fallow-argument-mismatch"
   ];
-});
+})