$OpenBSD: patch-src__cffi_src_build_openssl_py,v 1.3 2017/11/24 12:42:31 jca Exp $

  cc1: error: -Werror=sign-conversion: No option -Wsign-conversion

Index: src/_cffi_src/build_openssl.py
--- src/_cffi_src/build_openssl.py.orig
+++ src/_cffi_src/build_openssl.py
@@ -47,7 +47,7 @@ def _extra_compile_args(platform):
     revisit this.
     """
     if platform != "win32":
-        return ["-Wconversion", "-Wno-error=sign-conversion"]
+        return []
     else:
         return []
 
