From 091a9595f34cee856026e4451920d14e23ed0852 Mon Sep 17 00:00:00 2001
From: Niklas Korz <niklas@niklaskorz.de>
Date: Thu, 20 Feb 2025 19:04:43 +0100
Subject: [PATCH] buildRustCrate: make default value for codegenUnits
 configurable

---
 pkgs/build-support/rust/build-rust-crate/default.nix | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pkgs/build-support/rust/build-rust-crate/default.nix b/pkgs/build-support/rust/build-rust-crate/default.nix
index db9c2d784f6b..6b17568a81a6 100644
--- a/pkgs/build-support/rust/build-rust-crate/default.nix
+++ b/pkgs/build-support/rust/build-rust-crate/default.nix
@@ -13,6 +13,10 @@
 , cargo
 , jq
 , libiconv
+# Controls codegen parallelization for all crates.
+# May be overriden on a per-crate level.
+# See <https://doc.rust-lang.org/rustc/codegen-options/index.html#codegen-units>
+, defaultCodegenUnits ? 1
 }:
 
 let
@@ -339,7 +343,7 @@ crate_: lib.makeOverridable
       colors = lib.attrByPath [ "colors" ] "always" crate;
       extraLinkFlags = lib.concatStringsSep " " (crate.extraLinkFlags or [ ]);
       edition = crate.edition or null;
-      codegenUnits = if crate ? codegenUnits then crate.codegenUnits else 1;
+      codegenUnits = if crate ? codegenUnits then crate.codegenUnits else defaultCodegenUnits;
       extraRustcOpts =
         lib.optionals (crate ? extraRustcOpts) crate.extraRustcOpts
           ++ extraRustcOpts_