From 485bd961e444e2a82acc8a9d4a946b64d2b6eb45 Mon Sep 17 00:00:00 2001
From: Alexey Dubovskoy <dubovskoy.a@gmail.com>
Date: Mon, 13 Jul 2026 10:25:59 +0100
Subject: [PATCH] fix(build): use thin LTO to cut peak build memory

Fat LTO with codegen-units = 1 is the highest-peak-memory codegen
configuration available, and applying it across a ~400 crate graph needs
a multi-GB heap at link time. On low-memory ARM boards this OOMs, and
because cargo install writes its target dir into /tmp -- which Armbian
mounts on zram, sized to RAM/2 -- the resulting truncated rlib surfaces
as 'failed to load bitcode of module'.

Thin LTO keeps most of the optimisation benefit without the fat LTO
memory cliff, and dropping codegen-units = 1 restores codegen
parallelism.

Refs #366
---
 Cargo.toml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 7706f0b..89d2080 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -124,5 +124,6 @@ regex = "1"
 
 [profile.release]
 strip = true
-lto = true
-codegen-units = 1
+# Fat LTO with codegen-units = 1 needs a multi-GB heap to link this dependency
+# graph, which OOMs on low-memory ARM boards. See #366.
+lto = "thin"