Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.
Alternatively, you may set the environment variables MONO_MODULE_CFLAGS
and MONO_MODULE_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
中文 
WiFi Drivers 
No package 'mono' found
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.
Alternatively, you may set the environment variables MONO_MODULE_CFLAGS
and MONO_MODULE_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
我设置变量export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig还是不行，请指教，我是小白