Merge pull request #274804 from SomeoneSerge/feat/mpich-pmix

mpich: optional pmix support

nixos/doc/manual/release-notes/rl-2405.section.md

@@ -193,5 +193,7 @@ The pre-existing [services.ankisyncd](#opt-services.ankisyncd.enable) has been m
   replaces the need for the `extraPackages` option, this option will be
   deprecated in future releases.
 
+- The `mpich` package expression now requires `withPm` to be a list, e.g. `"hydra:gforker"` becomes `[ "hydra" "gforker" ]`.
+
 - QtMultimedia has changed its default backend to `QT_MEDIA_BACKEND=ffmpeg` (previously `gstreamer` on Linux or `darwin` on MacOS).
   The previous native backends remain available but are now minimally maintained. Refer to [upstream documentation](https://doc.qt.io/qt-6/qtmultimedia-index.html#ffmpeg-as-the-default-backend) for further details about each platform.

pkgs/development/libraries/mpich/default.nix

@@ -3,10 +3,19 @@
 # either libfabric or ucx work for ch4backend on linux. On darwin, neither of
 # these libraries currently build so this argument is ignored on Darwin.
 , ch4backend
-# Process manager to build
-, withPm ? "hydra:gforker"
+# Process managers to build (`--with-pm`),
+# cf. https://github.com/pmodels/mpich/blob/b80a6d7c24defe7cdf6c57c52430f8075a0a41d6/README.vin#L562-L586
+, withPm ? [ "hydra" "gforker" ]
+, pmix
+# PMIX support is likely incompatible with process managers (`--with-pm`)
+# https://github.com/NixOS/nixpkgs/pull/274804#discussion_r1432601476
+, pmixSupport ? false
 } :
 
+let
+  withPmStr = if withPm != [ ] then builtins.concatStringsSep ":" withPm else "no";
+in
+
 assert (ch4backend.pname == "ucx" || ch4backend.pname == "libfabric");
 
 stdenv.mkDerivation  rec {
@@ -22,11 +31,12 @@ stdenv.mkDerivation  rec {
 
   configureFlags = [
     "--enable-shared"
-    "--enable-sharedlib"
-    "--with-pm=${withPm}"
+    "--with-pm=${withPmStr}"
   ] ++ lib.optionals (lib.versionAtLeast gfortran.version "10") [
     "FFLAGS=-fallow-argument-mismatch" # https://github.com/pmodels/mpich/issues/4300
     "FCFLAGS=-fallow-argument-mismatch"
+  ] ++ lib.optionals pmixSupport [
+    "--with-pmix=${lib.getDev pmix}"
   ];
 
   enableParallelBuilding = true;
@@ -45,6 +55,9 @@ stdenv.mkDerivation  rec {
   '';
 
   meta = with lib; {
+    # As far as we know, --with-pmix silently disables all of `--with-pm`
+    broken = pmixSupport && withPm != [ ];
+
     description = "Implementation of the Message Passing Interface (MPI) standard";
 
     longDescription = ''

pkgs/top-level/all-packages.nix

@@ -24048,6 +24048,8 @@ with pkgs;
     ch4backend = libfabric;
   };
 
+  mpich-pmix = mpich.override { pmixSupport = true; withPm = [ ]; };
+
   mstpd = callPackage ../os-specific/linux/mstpd { };
 
   mtdev = callPackage ../development/libraries/mtdev { };