"Fatal undefined"

[alexgleason]

I'm trying to make a simple bot that responds to new members. I'm getting "Fatal undefined" which isn't helpful at solving the problem. Is there a way to better debug?

Thank you!

[marcinciarka]

I'm having the same issue and no response on this thread makes me worried :crying_cat_face:

[jryans]

Can you describe how you are using the SDK? I agree it sounds like an unhelpful error. Hopefully we can figure it out!

[marcinciarka]

(sry for reposting)

For me it's pretty basic stuff:

const sdk = require('matrix-js-sdk');
const myUserId = 'x';
const myAccessToken = 'xxx';
const matrixClient = sdk.createClient({
    baseUrl: 'xxx',
    accessToken: myAccessToken,
    userId: myUserId
});

matrixClient.on('sync', (syncState, a, event) => {
    console.log('syncState', syncState);
    console.log('event', event);
    console.log('a', a);
    
    if (syncState === 'PREPARED') {
        matrixClient.on("Room.timeline", function(event, room) {
            ('do stuff')
        });
    }
})

matrixClient.startClient();

node is outputting:

Got push rules
Sending first sync request...
syncState PREPARED
event { oldSyncToken: null,
  nextSyncToken: 'xxx',
  catchingUp: false }
a null
syncState SYNCING
event { oldSyncToken: null,
  nextSyncToken: 'xxx',
  catchingUp: false }
a PREPARED
Fatal undefined

[t3chguy]

            ('do stuff')

looks very invalid

What do you actually have here?

[marcinciarka]

('do stuff')

It's valid JS (I just cut out the irrelevant part...), but it doesn't matter, because nothing inside matrixClient.on('sync', () => {}) is being executed. Let's change this to:

    if (syncState === 'PREPARED') {
        matrixClient.on("Room.timeline", function(event, room) {
            console.log(event, room)
        });
    }

It just goes PREPARED => SYNCING and then Fatal undefined.

[marcinciarka]

After a little digging i've found out that the piece of code from the docs is causing the trouble:

   matrixClient.on("RoomMember.membership", function(event, member) {
       if (member.membership === "invite" && member.userId === myUserId) {
           matrixClient.joinRoom(member.roomId).done(function() {
               console.log("Auto-joined %s", member.roomId);
           });
       }
   });

But I'm not able to resolve this issue, so for the time being I will just comment this out.

--- EDIT

I've managed to gain more information - I've logged into riot web using the bot account and left the channel which was causing trouble. The bot was invited and then kicked from it.

[alexgleason]

I was also getting this error using a bot with only the auto-invite script just (like the comment above). Aside from matrixClient.start() or whatever, that was the only code.

It would crash right after starting, with the cryptic "Fatal undefined." Interesting that a room state could cause this.

EDIT: I had also kicked the bot from the room then re-invited it.