From e0d947c79c191d39fc120499d53916327c97d167 Mon Sep 17 00:00:00 2001
From: Doron Behar <doron.behar@gmail.com>
Date: Wed, 23 Sep 2020 00:52:45 +0300
Subject: [PATCH 1/2] arpack: cosmetic changes

Don't use `with stdenv.lib` at the top of the expression, per:
https://nix.dev/anti-patterns/language.html#with-attrset-expression

Use rec and version inside `mkDerivation`, like almost any other
derivation.
---
 .../libraries/science/math/arpack/default.nix         | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/pkgs/development/libraries/science/math/arpack/default.nix b/pkgs/development/libraries/science/math/arpack/default.nix
index 02d51f0c419..057a2d4b397 100644
--- a/pkgs/development/libraries/science/math/arpack/default.nix
+++ b/pkgs/development/libraries/science/math/arpack/default.nix
@@ -1,14 +1,9 @@
 { stdenv, fetchFromGitHub, cmake
 , gfortran, blas, lapack, eigen }:
 
-with stdenv.lib;
-
-let
-  version = "3.7.0";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "arpack";
-  inherit version;
+  version = "3.7.0";
 
   src = fetchFromGitHub {
     owner = "opencollab";
@@ -27,7 +22,7 @@ stdenv.mkDerivation {
 
   cmakeFlags = [
     "-DBUILD_SHARED_LIBS=ON"
-    "-DINTERFACE64=${optionalString blas.isILP64 "1"}"
+    "-DINTERFACE64=${stdenv.lib.optionalString blas.isILP64 "1"}"
   ];
 
   preCheck = if stdenv.isDarwin then ''

From bd77df6d6fdaea8ae0ab1f5581a76eb9db592e1d Mon Sep 17 00:00:00 2001
From: Doron Behar <doron.behar@gmail.com>
Date: Wed, 23 Sep 2020 00:56:00 +0300
Subject: [PATCH 2/2] arpack: assert that blas and lapack are compatible

Do it before buildInputs per:
https://github.com/NixOS/nixpkgs/pull/94892#discussion_r471110250

Remove unneed, BLAS_LIBS and LAPACK_LIBS from environment - the
libraries are detected just fine when in buildInputs.
---
 .../libraries/science/math/arpack/default.nix          | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/pkgs/development/libraries/science/math/arpack/default.nix b/pkgs/development/libraries/science/math/arpack/default.nix
index 057a2d4b397..0b927bb3eac 100644
--- a/pkgs/development/libraries/science/math/arpack/default.nix
+++ b/pkgs/development/libraries/science/math/arpack/default.nix
@@ -13,13 +13,15 @@ stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [ cmake ];
-  buildInputs = [ gfortran blas lapack eigen ];
+  buildInputs = assert (blas.isILP64 == lapack.isILP64); [
+    gfortran
+    blas
+    lapack
+    eigen
+  ];
 
   doCheck = true;
 
-  BLAS_LIBS = "-L${blas}/lib -lblas";
-  LAPACK_LIBS = "-L${lapack}/lib -llapack";
-
   cmakeFlags = [
     "-DBUILD_SHARED_LIBS=ON"
     "-DINTERFACE64=${stdenv.lib.optionalString blas.isILP64 "1"}"