From 7c8c71f8e9319b17e85c0f510bfd0d0558361ac2 Mon Sep 17 00:00:00 2001
From: Brian McKenna <brian@brianmckenna.org>
Date: Fri, 31 Jan 2025 21:11:45 +1100
Subject: [PATCH] Totally exclude nix::setStackSize on Windows

---
 src/libutil/current-process.cc | 4 ++--
 src/libutil/current-process.hh | 3 +++
 src/nix/main.cc                | 2 ++
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/libutil/current-process.cc b/src/libutil/current-process.cc
index 46e72b63a..255ae2cf5 100644
--- a/src/libutil/current-process.cc
+++ b/src/libutil/current-process.cc
@@ -51,11 +51,11 @@ unsigned int getMaxCPU()
 //////////////////////////////////////////////////////////////////////
 
 
+#ifndef _WIN32
 size_t savedStackSize = 0;
 
 void setStackSize(size_t stackSize)
 {
-    #ifndef _WIN32
     struct rlimit limit;
     if (getrlimit(RLIMIT_STACK, &limit) == 0 && limit.rlim_cur < stackSize) {
         savedStackSize = limit.rlim_cur;
@@ -73,8 +73,8 @@ void setStackSize(size_t stackSize)
             );
         }
     }
-    #endif
 }
+#endif
 
 void restoreProcessContext(bool restoreMounts)
 {
diff --git a/src/libutil/current-process.hh b/src/libutil/current-process.hh
index 8286bf89d..660dcfe0b 100644
--- a/src/libutil/current-process.hh
+++ b/src/libutil/current-process.hh
@@ -17,10 +17,13 @@ namespace nix {
  */
 unsigned int getMaxCPU();
 
+// It does not seem possible to dynamically change stack size on Windows.
+#ifndef _WIN32
 /**
  * Change the stack size.
  */
 void setStackSize(size_t stackSize);
+#endif
 
 /**
  * Restore the original inherited Unix process context (such as signal
diff --git a/src/nix/main.cc b/src/nix/main.cc
index b0e26e093..80ef53084 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -557,9 +557,11 @@ void mainWrapped(int argc, char * * argv)
 
 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);
+#endif
 
     return nix::handleExceptions(argv[0], [&]() {
         nix::mainWrapped(argc, argv);