From 08e218eb0b315bf176923dd331318c8c28d270b7 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Tue, 4 Nov 2025 22:51:33 +0100
Subject: [PATCH] Reduce the stack size to a bit under 64 MiB

---
 src/nix/main.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/nix/main.cc b/src/nix/main.cc
index 74d22e433..217e5fa9b 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -566,7 +566,9 @@ int main(int argc, char ** argv)
 #ifndef _WIN32
     // Increase the default stack size for the evaluator and for
     // libstdc++'s std::regex.
-    nix::setStackSize(64 * 1024 * 1024);
+    // This used to be 64 MiB, but macOS as deployed on GitHub Actions has a
+    // hard limit slightly under that, so we round it down a bit.
+    nix::setStackSize(60 * 1024 * 1024);
 #endif
 
     return nix::handleExceptions(argv[0], [&]() { nix::mainWrapped(argc, argv); });