diff --git a/flake.nix b/flake.nix
index 435209927d..19ecb10ed4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -49,14 +49,17 @@
 
         basePkg = {
           name,
-          nativeBuildInputs,
-          buildInputs,
-          cmakeFlags,
+          nativeBuildInputs ? [],
+          buildInputs ? [],
+          cmakeFlags ? [],
           doCheck,
-          checkOptions,
+          checkOptions ? ''-L "quick|fast" -E "(ForceToStress_parallel)|(Hydro_Coupled)|(Hydro_SedOnly)|(Proj_South)|(.*_np[3-9])"'',
           ...
-        } @ inputs: let
+        }: let
           storepath = placeholder "out";
+          extraNativeBuildInputs = nativeBuildInputs;
+          extraBuildInputs = buildInputs;
+          extraCmakeFlags = cmakeFlags;
         in
           pkgs.stdenv.mkDerivation {
             inherit name doCheck storepath;
@@ -86,7 +89,7 @@
                 pkg-config
                 autoPatchelfHook
               ]
-              ++ inputs.nativeBuildInputs;
+              ++ extraNativeBuildInputs;
 
             buildInputs = with pkgs;
               [
@@ -95,7 +98,7 @@
                 liblapack
                 tbb
               ]
-              ++ inputs.buildInputs;
+              ++ extraBuildInputs;
 
             cmakeFlags =
               [
@@ -110,7 +113,7 @@
 
                 "-Wno-dev"
               ]
-              ++ inputs.cmakeFlags;
+              ++ extraCmakeFlags;
 
             checkPhase = ''
               runHook preCheckPhase
@@ -130,24 +133,15 @@
             ];
           };
 
-        default = {
-          doCheck ? false,
-          checkOptions ? ''-L "quick|fast" -E "(ForceToStress_parallel)|(Hydro_Coupled)|(Hydro_SedOnly)|(Proj_South)|(PoissonDG_np8)|(poisson_transient_conforming_anti_np8)"'',
-        }:
+        default = {doCheck ? false}:
           basePkg {
-            inherit doCheck checkOptions;
+            inherit doCheck;
             name = "elmer";
-            nativeBuildInputs = [];
-            buildInputs = [];
-            cmakeFlags = [];
           };
 
-        gui = {
-          doCheck ? false,
-          checkOptions ? ''-L "quick|fast" -E "(ForceToStress_parallel)|(Hydro_Coupled)|(Hydro_SedOnly)|(Proj_South)|(PoissonDG_np8)|(poisson_transient_conforming_anti_np8)"'',
-        }:
+        gui = {doCheck ? false}:
           basePkg {
-            inherit doCheck checkOptions;
+            inherit doCheck;
             name = "elmer-gui";
 
             nativeBuildInputs = [pkgs.libsForQt5.wrapQtAppsHook];
@@ -171,16 +165,11 @@
             ];
           };
 
-        full = {
-          doCheck ? false,
-          checkOptions ? ''-L "quick|fast" -E "(ForceToStress_parallel)|(Hydro_Coupled)|(Hydro_SedOnly)|(Proj_South)|(PoissonDG_np8)|(poisson_transient_conforming_anti_np8)"'',
-        }:
+        full = {doCheck ? false}:
           basePkg {
-            inherit doCheck checkOptions;
+            inherit doCheck;
             name = "elmer-full";
 
-            nativeBuildInputs = [];
-
             buildInputs = with pkgs;
               [
                 hdf5-mpi
@@ -196,8 +185,8 @@
             cmakeFlags = [
               "-DWITH_NETCDF:BOOL=TRUE"
               "-DNETCDF_LIBRARY=${pkgs.netcdf-mpi}/lib/libnetcdf.so"
-              "-DNETCDFF_LIBRARY=${pkgs.netcdffortran}/lib/libnetcdff.so"
               "-DNETCDF_INCLUDE_DIR=${pkgs.netcdf-mpi}/include"
+              "-DNETCDFF_LIBRARY=${pkgs.netcdffortran}/lib/libnetcdff.so"
               "-DCMAKE_Fortran_FLAGS=-I${pkgs.netcdffortran}/include"
 
               "-DWITH_Hypre:BOOL=TRUE"
@@ -205,8 +194,10 @@
               "-DWITH_Mumps:BOOL=TRUE"
 
               "-DWITH_ScatteredDataInterpolator:BOOL=TRUE"
+
               "-DCSA_LIBRARY=${csa}/lib/libcsa.a"
               "-DCSA_INCLUDE_DIR=${csa}/include"
+
               "-DNN_INCLUDE_DIR=${pkgs.nn}/include"
               "-DNN_LIBRARY=${pkgs.nn}/lib/libnn.a"