12.9.0 MaxListenersExceededWarning

[XhmikosR]

• Version: v12.9.0
• Platform: All platforms [This line edited by @Trott to help people arriving at this issue/]

Started to happen after updating to 12.9.0. I'm getting:

MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit

even when doing npm i in a project:

C:\Users\xmr\Desktop\bootstrapcdn>npm i
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:3860) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
...

Going back to 12.8.1 and the warnings are gone.

[mscdex]

Do you have a minimal code example to reproduce this?

[XhmikosR]

Sorry, I don't :/ I just noticed this with a simple npm install.

[ex1st]

Simple to reproduce:

npm i -g grunt-cli
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
(node:31849) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
/home/ex1st/.nvm/versions/node/v12.9.0/bin/grunt -> /home/ex1st/.nvm/versions/node/v12.9.0/lib/node_modules/grunt-cli/bin/grunt
+ grunt-cli@1.3.2
updated 1 package in 3.342s

[targos]

I can reproduce.

Here's the stack trace:

(node:1445) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [TLSSocket]. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:267:17)
    at TLSSocket.addListener (events.js:283:10)
    at TLSSocket.Readable.on (_stream_readable.js:863:35)
    at tickOnSocket (_http_client.js:670:10)
    at onSocketNT (_http_client.js:717:5)
    at processTicksAndRejections (internal/process/task_queues.js:77:11)

[targos]

_http_client.js:670 points to #29081

/cc @ronag @mcollina

[ex1st]

Hi @targos, I've caught same warning on Linux.

[ronag]

I suspect I know what it is. My computer broke so I need to sort that out. Will have a PR later today.

[mcollina]

@targos let’s do a revert with fast-track and get 12.9.1 out of the door asap :/.

[Trott]

@targos let’s do a revert with fast-track and get 12.9.1 out of the door asap :/.

Revert PR is in #29244