Show reason non-default renderer failed to load.

code/client/cl_main.c

@@ -3201,6 +3201,7 @@ void CL_InitRef( void ) {
 
 	if(!(rendererLib = Sys_LoadDll(dllName, qfalse)) && strcmp(cl_renderer->string, cl_renderer->resetString))
 	{
+		Com_Printf("failed:\n\"%s\"\n", Sys_LibraryError());
 		Cvar_ForceReset("cl_renderer");
 
 		Com_sprintf(dllName, sizeof(dllName), "renderer_opengl1_" ARCH_STRING DLL_EXT);