屏幕Xcode 8多余日志输出

问题：

升级Xcode 8之后，运行项目，控制台总是打印多余的日志，如下：

nw_socket_set_common_sockopts setsockopt SO_NOAPNFALLBK failed: [42] Protocol not available, dumping backtrace:
        [x86_64] libnetcore-856.1.8
    0   libsystem_network.dylib             0x000000010b23380e __nw_create_backtrace_string + 123
    1   libnetwork.dylib                    0x000000010c032194 nw_socket_add_input_handler + 3002
    2   libnetwork.dylib                    0x000000010c00fdb8 nw_endpoint_flow_attach_protocols + 3768
    3   libnetwork.dylib                    0x000000010c00edd5 nw_endpoint_flow_setup_socket + 563
    4   libnetwork.dylib                    0x000000010c00db34 -[NWConcrete_nw_endpoint_flow startWithHandler:] + 2612
    5   libnetwork.dylib                    0x000000010c028d11 nw_endpoint_handler_path_change + 1261
    6   libnetwork.dylib                    0x000000010c028740 nw_endpoint_handler_start + 570
    7   libnetwork.dylib                    0x000000010c040003 nw_endpoint_resolver_start_next_child + 2240
    8   libdispatch.dylib                   0x000000

解决：

1. 打开Edit Scheme

Edit Scheme.png

添加环境变量.png