$OpenBSD: patch-vcl_Executable_vcldemo_mk,v 1.1 2015/05/03 11:30:33 robert Exp $
--- vcl/Executable_vcldemo.mk.orig.port	Mon Apr  6 15:44:30 2015
+++ vcl/Executable_vcldemo.mk	Mon Apr  6 15:44:47 2015
@@ -42,10 +42,10 @@ $(eval $(call gb_Executable_use_static_libraries,vclde
     vclmain \
 ))
 
-ifeq ($(OS),LINUX)
+ifneq (,$(filter LINUX OPENBSD,$(OS)))
 $(eval $(call gb_Executable_add_libs,vcldemo,\
 	-lm \
-	-ldl \
+	$(if $(filter LINUX,$(OS)),-ldl) \
 	-lpthread \
     -lGL \
     -lGLU \
