From 855f2d04358991a8cd10d4f7b5ff9e0b0ea53901 Mon Sep 17 00:00:00 2001
From: Eman Resu <78693624+quatquatt@users.noreply.github.com>
Date: Tue, 26 May 2026 13:23:00 -0400
Subject: [PATCH] lib.strings: remove assertMsg usage

assertMsg sends our error message through a function call, even if the
error condition doesn't trigger. This requires a lot of thunk allocation
that can be easily avoided.
---
 lib/strings.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/strings.nix b/lib/strings.nix
index b81a04a6666b..a926edfaeba6 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -2532,8 +2532,9 @@ rec {
       strw = lib.stringLength str;
       reqWidth = width - (lib.stringLength filler);
     in
-    assert lib.assertMsg (strw <= width)
-      "fixedWidthString: requested string length (${toString width}) must not be shorter than actual length (${toString strw})";
+    assert
+      strw <= width
+      || throw "fixedWidthString: requested string length (${toString width}) must not be shorter than actual length (${toString strw})";
     if strw == width then str else filler + fixedWidthString reqWidth filler str;
 
   /**