- stub some functions implementation so it compiles
- we don't seem to have pthread_getaffinity_np in pthread_np.h; use
  sysctl like macos and andoid then

Index: thirdparty/embree/common/sys/sysinfo.cpp
--- thirdparty/embree/common/sys/sysinfo.cpp.orig
+++ thirdparty/embree/common/sys/sysinfo.cpp
@@ -603,6 +603,26 @@ namespace embree
 
 #endif
 
+#if defined(__OpenBSD__)
+namespace embree
+{
+	std::string getExecutableFileName()
+	{
+		return "";
+	}
+
+	size_t getVirtualMemoryBytes()
+	{
+		return 0;
+	}
+
+	size_t getResidentMemoryBytes()
+	{
+		return 0;
+	}
+}
+#endif
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Mac OS X Platform
 ////////////////////////////////////////////////////////////////////////////////
@@ -661,7 +681,7 @@ namespace embree
     static int nThreads = -1;
     if (nThreads != -1) return nThreads;
 
-#if defined(__MACOSX__) || defined(__ANDROID__)
+#if defined(__MACOSX__) || defined(__ANDROID__) || defined(__OpenBSD__)
     nThreads = sysconf(_SC_NPROCESSORS_ONLN); // does not work in Linux LXC container
     assert(nThreads);
 #elif defined(__EMSCRIPTEN__)
