From c3a5f937d374d9b2e6aee93bbec7b6786b7c1457 Mon Sep 17 00:00:00 2001
From: eldritch horrors <pennae@lix.systems>
Date: Mon, 25 Mar 2024 22:16:38 +0100
Subject: [PATCH] flake.nix: linearize meson builds

parallel meson builds need too much ram. linearize them for now, and
hopefully we can remove the make build system and this hack soonish.

Change-Id: I42c092db8b0c63680e77da2263cdfe9e7f6575be
---
 flake.nix | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/flake.nix b/flake.nix
index 5ab36408b..21d6de9e8 100644
--- a/flake.nix
+++ b/flake.nix
@@ -205,13 +205,20 @@
         build = forAllSystems (system: self.packages.${system}.nix);
 
         # FIXME(Qyriad): remove this when the migration to Meson has been completed.
-        mesonBuild = forAllSystems (system: self.packages.${system}.nix.override {
-          buildWithMeson = true;
-        });
+        # NOTE: mesonBuildClang depends on mesonBuild depends on build to avoid OOMs
+        # on aarch64 builders caused by too many parallel compiler/linker processes.
+        mesonBuild = forAllSystems (system:
+          (self.packages.${system}.nix.override {
+            buildWithMeson = true;
+          }).overrideAttrs (prev: {
+            buildInputs = prev.buildInputs ++ [ self.packages.${system}.nix ];
+          }));
         mesonBuildClang = forAllSystems (system:
-            nixpkgsFor.${system}.stdenvs.clangStdenvPackages.nix.override {
+          (nixpkgsFor.${system}.stdenvs.clangStdenvPackages.nix.override {
               buildWithMeson = true;
-            }
+          }).overrideAttrs (prev: {
+            buildInputs = prev.buildInputs ++ [ self.hydraJobs.mesonBuild.${system} ];
+          })
         );
 
         # Perl bindings for various platforms.