Threads.expose is called to late - "Did not receive an init message from worker after 10000ms" on clean 1.8.16 install

Clean install of etherpad-lite 1.8.16 fails to run on alpine edge in an lxc container on armhf architecture. The same command chain on a x86_64 succeeds (sic!).

I’m quite lost where to look for a solution to this problem, especially that the SBC (banana pro) that etherpad fails to start on is slow.

What I see on the first request from any web browser is:

[2022-01-26 12:38:09.239] [INFO] server - Etherpad is running
[2022-01-26 12:38:35.968] [ERROR] console - Error: Timeout: Did not receive an init message from worker after 10000ms. Make sure the worker calls expose().
    at Timeout._onTimeout (/var/etherpad-lite-1.8.16/src/node_modules/threads/dist/master/spawn.js:35:53)
    at listOnTimeout (node:internal/timers:557:17)
    at processTimers (node:internal/timers:500:7)

The error repeats multiple times at once. The error appears almost immediately after entering container IP in a web browser, not after the 10 seconds that the message mentions.

Node.js versions tested: 16.13.2 and 17.4.0

To Reproduce

1. lxc-create -t download -n ep
   1. Distribution: alpine
   2. Release: edge
   3. Architecture: armhf
2. lxc-start ep && lxc-attach ep
3. apk update
4. apk add nodejs npm build-base python3 sqlite # extra packages are needed due to ep dependencies
5. wget https://github.com/ether/etherpad-lite/archive/1.8.16.zip
6. unzip 1.8.16.zip
7. cd etherpad-lite-1.8.16
8. cp settings.json.template settings.json
9. vi settings.json # added an admin user and changed the port to 80
10. ./bin/run.sh --root

Server

• Etherpad version: 1.8.16 (I hit the problem first with current development branch, then tried a clean install once all else failed)
• OS: alpine in lxc (run in debian testing, but I doubt this matters)
• Hardware: armhf, sun7i-a20-bananapro
• Node.js version: v16.13.2 (upgrading to 17.4.0 did not help either)
• npm version: 8.3.0
• Is the server free of plugins: yes

Additional For some reason installing dependencies compiles sqlite3 (for node-pre-gyp fails to find precompiled binaries), and so installing dependencies takes way too long.

I ended up hitting this issue on an upgrade from etherpad-lite1.8.0-beta.1 running on node v12.13.1 in another alpine container on the same machine that now fails to run current etherpad-lite & node. Simple upgrade failed with the same results, so I tried a clean install and it fails the same way…

[deurbroucq]

@rhansen No, I am not running on armhf. I am running on x86_64. However, the minify workaround in settings.json worked for me too! Thank you!

[anonymous-14523]

(you can skip to past the last <hr>)

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To confirm I understand correctly:

Etherpad 1.8.0-beta.1 on Node.js v12.13.1 works on armhf. Etherpad 1.8.16 on Node.js v16.13.2 (or v17.4.0) does not work on armhf.

Yes.

Is that correct? If so, can you try bisecting to identify the commit causing it to fail?

Hm… this is theoretically possible, for I tested right now that 1.8.0-beta.1 still works with updated node (v16.13.2).

The practical problem that refrains me from this is that new node (1.8.16) needs something that needs sqlite3. Now the problem is that node-pre-gyp finds no pre-build binaries for sqlite3 and compiles it itself, and so installing dependencies takes half an hour (that arm is old and sqlite3 alone compiles about 3 minutes on my desktop…).

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> require('./node/utils/MinifyWorker')

This seems fine, I get similar error (line numbers slightly differ, though):

Welcome to Node.js v16.13.2.
Type ".help" for more information.
> require('./node/utils/MinifyWorker')
Uncaught Error: expose() called in the master thread.
    at Object.expose (/var/etherpad-lite/src/node_modules/threads/dist/worker/index.js:146:15)
    at Object.<anonymous> (/var/etherpad-lite/src/node/utils/MinifyWorker.js:30:9)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
>

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A possible workaround is to set the following in your settings.json:

  "minify": false,

Wow! This worked! 👍

Also: this significantly speeds up loading time: tell me, does etherpad cache minifed js, or minifies it frequently?

(I’m fine with this workround, so the issue might be closed.)