--- mesa-17.2.0-rc5/src/gallium/drivers/swr/rasterizer/core/utils.h.omv~	2017-08-31 00:39:53.063561929 +0200
+++ mesa-17.2.0-rc5/src/gallium/drivers/swr/rasterizer/core/utils.h	2017-08-31 00:40:13.853833494 +0200
@@ -347,7 +347,8 @@ static INLINE std::string GetEnv(const s
     output.resize(valueSize - 1); // valueSize includes null, output.resize() does not
     GetEnvironmentVariableA(variableName.c_str(), &output[0], valueSize);
 #else
-    output = getenv(variableName.c_str());
+    char *o = getenv(variableName.c_str());
+    output = o ? std::string(o) : std::string();
 #endif
 
     return output;