From 01c82ddd15790d54ff3bc1c12c408944159e26a5 Mon Sep 17 00:00:00 2001
From: qbisi <qbisicwate@gmail.com>
Date: Sat, 22 Nov 2025 01:03:41 +0800
Subject: [PATCH] fftwMpi: link explicitly against -lmpi

---
 pkgs/by-name/ff/fftw/package.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/by-name/ff/fftw/package.nix b/pkgs/by-name/ff/fftw/package.nix
index 4c34f1c330af..c0d2ddcfde9d 100644
--- a/pkgs/by-name/ff/fftw/package.nix
+++ b/pkgs/by-name/ff/fftw/package.nix
@@ -69,7 +69,15 @@ stdenv.mkDerivation (finalAttrs: {
   ++ lib.optional (
     stdenv.hostPlatform.isx86_64 && (precision == "single" || precision == "double")
   ) "--enable-sse2 --enable-avx --enable-avx2 --enable-avx512 --enable-avx128-fma"
-  ++ lib.optional enableMpi "--enable-mpi"
+  ++ lib.optionals enableMpi [
+    "--enable-mpi"
+    # link libfftw3_mpi explicitly with -lmpi
+    # linker on darwin requires all symbols to be resolvable at link time
+    # see
+    #   https://github.com/FFTW/fftw3/issues/274
+    #   https://github.com/spack/spack/pull/29279
+    "MPILIBS=-lmpi"
+  ]
   # doc generation causes Fortran wrapper generation which hard-codes gcc
   ++ lib.optional (!withDoc) "--disable-doc";