From 96a36833084f66b79ba778e719862b8219557773 Mon Sep 17 00:00:00 2001
From: eldritch horrors <pennae@lix.systems>
Date: Mon, 4 Mar 2024 09:03:49 +0100
Subject: [PATCH] Ban building Nix with NDEBUG

When reviewing old PRs, I found that #9997 adds some code to ensure one
particular assert is always present. But, removing asserts isn't
something we do in our own release builds either in the flake here or in
nixpkgs, and is plainly a bad idea that increases support burden,
especially if other distros make bad choices of build flags in their Nix
packaging.

For context, the assert macro in the C standard is defined to do nothing
if NDEBUG is set.

There is no way in our build system to set -DNDEBUG without manually
adding it to CFLAGS, so this is simply a configuration we do not use.
Let's ban it at compile time.

I put this preprocessor directive in src/libutil.cc because it is not
obvious where else to put it, and it seems like the most logical file
since you are not getting a usable nix without it.

Upstream-PR: https://github.com/NixOS/nix/pull/10126
Original-Change-Id: I513cceaac1371decb3d96231e6ef9181c910c218
Change-Id: I531a51f6348a746e8e41d88203b08f614898356c
---
 src/libutil/util.cc                 | 4 ++++
 tests/unit/libstore/outputs-spec.cc | 2 --
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 3b4c181e5..baff6624c 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -45,6 +45,10 @@
 extern char * * environ __attribute__((weak));
 
 
+#ifdef NDEBUG
+#error "Nix may not be built with assertions disabled (i.e. with -DNDEBUG)."
+#endif
+
 namespace nix {
 
 void initLibUtil() {
diff --git a/tests/unit/libstore/outputs-spec.cc b/tests/unit/libstore/outputs-spec.cc
index 456196be1..63cde681b 100644
--- a/tests/unit/libstore/outputs-spec.cc
+++ b/tests/unit/libstore/outputs-spec.cc
@@ -6,11 +6,9 @@
 
 namespace nix {
 
-#ifndef NDEBUG
 TEST(OutputsSpec, no_empty_names) {
     ASSERT_DEATH(OutputsSpec::Names { std::set<std::string> { } }, "");
 }
-#endif
 
 #define TEST_DONT_PARSE(NAME, STR)           \
     TEST(OutputsSpec, bad_ ## NAME) {        \