From 508ab3bd8cde0cf30f6d03e18dfd0e5a55aa7758 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Fri, 13 Jun 2025 15:29:45 +0200
Subject: [PATCH] New CPPDUALS: re-enable compiling with CYGWIN

---
 src/include/cppduals/duals/dual | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/include/cppduals/duals/dual b/src/include/cppduals/duals/dual
index 94688d185..4cb227e84 100644
--- a/src/include/cppduals/duals/dual
+++ b/src/include/cppduals/duals/dual
@@ -44,9 +44,11 @@ _LIBCPP_END_NAMESPACE_STD
 /// Configure whether system has POSIX extern int signgam;
 #ifndef CPPDUALS_HAVE_SIGNGAM
 #ifndef _WIN32
+#ifndef __CYGWIN__
 #define CPPDUALS_HAVE_SIGNGAM 1
 #endif
 #endif
+#endif
 namespace duals {
 
 /**