nixpkgs/pkgs/development/libraries/armadillo/use-unix-config-on-OS-X.patch

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -152,6 +152,7 @@ message(STATUS "DETECT_HDF5                = ${DETECT_HDF5}"               )

 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake_aux/Modules/")

+set(APPLE false)
 if(APPLE)
   
   set(ARMA_OS macos)