Electron Error: Cannot open display :0

rudibarani · Oct 4, 2018, 4:30 PM

Dear all,
I have tried to setup MM2 about 20 times by now and always run into exactly the same error:

pi@MirrorPi:~ $ cd MagicMirror/
pi@MirrorPi:~/MagicMirror $ DISPLAY=:0 npm start

> magicmirror@2.5.0 start /home/pi/MagicMirror
> sh run-start.sh

(electron:24936): Gtk-WARNING **: cannot open display: :0
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! magicmirror@2.5.0 start: `sh run-start.sh`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the magicmirror@2.5.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/pi/.npm/_logs/2018-10-03T21_35_33_903Z-debug.log

The Log-File states:

info it worked if it ends with ok
1 verbose cli [ '/usr/bin/node', '/usr/bin/npm', 'start' ]
2 info using npm@6.4.1
3 info using node@v10.11.0
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle magicmirror@2.5.0~prestart: magicmirror@2.5.0
6 info lifecycle magicmirror@2.5.0~start: magicmirror@2.5.0
7 verbose lifecycle magicmirror@2.5.0~start: unsafe-perm in lifecycle true
8 verbose lifecycle magicmirror@2.5.0~start: PATH: /usr/lib/node_modules/npm/node_modules/npm-lifecycle/node-gyp-bin:/home/pi/MagicMirror/node_modules/.bin:/usr/local/sb$
9 verbose lifecycle magicmirror@2.5.0~start: CWD: /home/pi/MagicMirror
10 silly lifecycle magicmirror@2.5.0~start: Args: [ '-c', 'sh run-start.sh' ]
11 silly lifecycle magicmirror@2.5.0~start: Returned: code: 1  signal: null
12 info lifecycle magicmirror@2.5.0~start: Failed to exec start script
13 verbose stack Error: magicmirror@2.5.0 start: `sh run-start.sh`
13 verbose stack Exit status 1
13 verbose stack     at EventEmitter.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:301:16)
13 verbose stack     at EventEmitter.emit (events.js:182:13)
13 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:182:13)
13 verbose stack     at maybeClose (internal/child_process.js:962:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:251:5)
14 verbose pkgid magicmirror@2.5.0
15 verbose cwd /home/pi/MagicMirror
16 verbose Linux 4.14.70-v7+
17 verbose argv "/usr/bin/node" "/usr/bin/npm" "start"
18 verbose node v10.11.0
19 verbose npm  v6.4.1
20 error code ELIFECYCLE
21 error errno 1

My setup process is:

clean install of latest image of Raspian stretch
setup wifi, keyboard, CLI-boot
sudo apt-get update && sudo apt-get upgrade
set memory-split to 256
activate Fake KMS
install latest versions of NodeJS (via apt-get) and npm (via npm)
install MM2 via raspberry.sh script

I do not get any error messages during setup.

I also tried the manual setup several times with the same result and even tried different Pis, SD cards and Monitors. Setting up the system on-site or via SSH does not make a difference either.

Searching the internet did not get me very far. What I tried without success:

export DISPLAY=":0.0"
export DISPLAY=":0"
xhost +–> unable to open display “:0”
xhost local:root --> unable to open display “:0”
xhost +localhost --> unable to open display “:0”
adding Defaults env_keep=DISPLAY in /etc/sudoers
adding export XAUTHORITY=$HOME/.Xauthority in /home/pi/.bashrc

Do you have any idea how to solve this?

bream · Oct 7, 2018, 9:27 AM

I had the same error, and the problem turned out to be that on first boot I had decided to reconfigure the pi to boot to the console rather than the desktop. Consequently I didn’t have a x server running (doh!)
You didn’t mention that as one of your setup steps, but I though it might be worth mentioning.

sdetweil · Oct 5, 2018, 12:33 PM

@rudibarani said in Electron Error: Cannot open display :0:

setup wifi, keyboard, CLI-boot

you ARE running the GUI desktop, right… NOT commandline.

bream · Oct 5, 2018, 1:30 PM

I am now :)

rudibarani · Oct 7, 2018, 9:27 AM

@bream @sdetweil Thank you very much for your reply! This could be the right path! I have initially configured the Pi on the GUI surface (Wifi, Keyboard) and then switched to CLI boot. I have done this with my previous installations of MagicMirror without problems, as electron started the x-server as needed. This does not seem to work anymore…

How do I revert this? I have changed back from CLI-boot to Desktop GUI in raspi-config. If I ssh into the pi and start MagicMirror via DISPLAY=:0 npm start, the application claims to start without problems:

> magicmirror@2.5.0 start /home/pi/MagicMirror
> sh run-start.sh

Starting MagicMirror: v2.5.0
Loading config ...
Loading module helpers ...
No helper found for module: alert.
Initializing new module helper ...
Module helper loaded: updatenotification
No helper found for module: clock.
Initializing new module helper ...
Module helper loaded: calendar
No helper found for module: compliments.
No helper found for module: currentweather.
No helper found for module: weatherforecast.
Initializing new module helper ...
Module helper loaded: newsfeed
All module helpers loaded.
Starting server on port 8080 ... 
Server started ...
Connecting socket for: updatenotification
Connecting socket for: calendar
Starting node helper for: calendar
Connecting socket for: newsfeed
Starting module: newsfeed
Sockets connected & modules started ...
Launching application.

Unfortunately, the display still just shows the GUI of the operation system.
Could you please help me from here?

Thank you very much!

sdetweil · Oct 14, 2018, 3:39 PM

@rudibarani i only do npm start from my ssh session

do u have a keyboard on the pi? if so, ctrl-alt-t will open a shell window… then u should be able to get to the previous command with up arrow…