gpio-admin: could not flush data to /sys/class/gpio/unexport: Invalid argument

[this-self]

Hi. I have latest updated raspbian on my Raspberry Pi 3 model B.

    .',;:cc;,'.    .,;::c:,,.    pi@raspberrypi
   ,ooolcloooo:  'oooooccloo:    OS: Unknown 8.0 jessie
   .looooc;;:ol  :oc;;:ooooo'    Kernel: armv7l Linux 4.9.35-v7+
     ;oooooo:      ,ooooooc.     Uptime: 52m
       .,:;'.       .;:;'.       Packages: 1254
       .... ..'''''. ....        Shell: 1411
     .''.   ..'''''.  ..''.      CPU: ARMv7 rev 4 (v7l) @ 1.2GHz
     ..  .....    .....  ..      RAM: 116MB / 923MB
    .  .'''''''  .''''''.  .
  .'' .''''''''  .'''''''. ''.
  '''  '''''''    .''''''  '''
  .'    ........... ...    .'.
    ....    ''''''''.   .''.
    '''''.  ''''''''. .'''''
     '''''.  .'''''. .'''''.
      ..''.     .    .''..
            .'''''''
             ......

I have this small example code:

const gpio = require("pi-gpio");
const log = new (require ("ex-logger")).Logger();

log.d("init");

gpio.open(8, "output", (err) => {
    log.d("opened 8");
    gpio.write(8, 1, () => {
        log.d("wrote 8");
        gpio.close(8);
        log.i("closed 8");
    });
});

And I have this log output:

[2017/07/27][07:08:11][D][file.js][4] init
Error when trying to open pin 8
gpio-admin: failed to change group ownership of /sys/devices/virtual/gpio/gpio14/direction: No such file or directory

[2017/07/27][07:08:11][D][file.js][7] opened 8
[2017/07/27][07:08:11][D][file.js][9] wrote 8
[2017/07/27][07:08:11][I][file.js][11] closed 8

Of course, not any signal on 8th gpio pin.

[this-self]

Oh, sorry. This issue in most for gpio-admin library.
Here is pull request for gpio-admin for resolving it.