Electron example fails with "node-pre-gyp info This Node instance does not support builds for N-API version 4"

[ksabr]

Hi there,

I'm running into the issue described in #2370 when trying to run the electron example in tfjs-examples, but the recipes given there do not appear to help. Some more info below:

TensorFlow.js version

1.3.2

Browser version

74.0.3729.131

Node version

12.9.1 (also tried 10.13.0, 10.16.3)

Platform

CentOS Linux release 7.6.1810 (Core)

Describe the problem or feature request

Running the electron example at https://github.com/tensorflow/tfjs-examples/tree/master/electron results in:

node-pre-gyp info This Node instance does not support builds for N-API version 4
node-pre-gyp info This Node instance does not support builds for N-API version 4
App threw an error during load
Error: Cannot find module '/home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/lib/napi-v3/tfjs_binding.node'
    at Module._resolveFilename (internal/modules/cjs/loader.js:584:15)
    at Function.Module._resolveFilename (/home/research/tfjs-examples/electron/node_modules/electron/dist/resources/electron.asar/common/reset-search-paths.js:43:12)
    at Function.Module._load (internal/modules/cjs/loader.js:510:25)
    at Module.require (internal/modules/cjs/loader.js:640:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (/home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/dist/index.js:44:16)
    at Object.<anonymous> (/home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/dist/index.js:66:3)
    at Module._compile (internal/modules/cjs/loader.js:693:30)
    at Object.require.extensions.(anonymous function) [as .js] (/home/research/tfjs-examples/electron/node_modules/electron-compile/lib/require-hook.js:77:14)
    at Module.load (internal/modules/cjs/loader.js:602:32)
A JavaScript error occurred in the main process
Uncaught Exception:
Error: Cannot find module '/home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/lib/napi-v3/tfjs_binding.node'
    at Module._resolveFilename (internal/modules/cjs/loader.js:584:15)
    at Function.Module._resolveFilename (/home/research/tfjs-examples/electron/node_modules/electron/dist/resources/electron.asar/common/reset-search-paths.js:43:12)
    at Function.Module._load (internal/modules/cjs/loader.js:510:25)
    at Module.require (internal/modules/cjs/loader.js:640:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (/home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/dist/index.js:44:16)
    at Object.<anonymous> (/home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/dist/index.js:66:3)
    at Module._compile (internal/modules/cjs/loader.js:693:30)
    at Object.require.extensions.(anonymous function) [as .js] (/home/research/tfjs-examples/electron/node_modules/electron-compile/lib/require-hook.js:77:14)
    at Module.load (internal/modules/cjs/loader.js:602:32)

---

npm rebuild @tensorflow/tfjs-node --build-from-source seems to run fine but doesn't fix the problem. The mnist-node example runs without issues. Please let me know if you have any idea what could be going wrong.

[kangyizhang]

hi @ksabr , can you take a look of what is in the path /home/research/tfjs-examples/electron/node_modules/@tensorflow/tfjs-node/lib?

[ksabr]

Hi @kangyizhang ,

There's a directory napi-v4 in there so clearly something is confusing node-pre-gyp. Looking into it a bit deeper, I discovered that modifying the module.exports.get_napi_version function in node_modules/node-pre-gyp/lib/util/napi.js (see https://github.com/mapbox/node-pre-gyp/blob/ef634f92f562cde064fbf831896fef045a47f9a1/lib/util/napi.js#L29) manually to return the value '4' makes the code run. As it is, the function returns '3' for some mysterious reason. This is despite this piece of code returning 4 as I'd expect:

var version = process.versions.napi;
console.log(version);

Any ideas why node-pre-gyp is behaving this way? Many thanks!

[kangyizhang]

node version 12.9.1 should be napi v5. can you try node version 12.13.0 and @tensorflow/tfjs-node version 1.4.0?

[ksabr]

Hi @kangyizhang ,

With node 12.13.0 and "@tensorflow/tfjs-node": "^1.4.0", in package.json I get:

yarn run v1.21.1
$ electron .
node-pre-gyp info This Node instance does not support builds for N-API version 4
node-pre-gyp info This Node instance does not support builds for N-API version 5
node-pre-gyp info This Node instance does not support builds for N-API version 4
node-pre-gyp info This Node instance does not support builds for N-API version 5
App threw an error during load

For what it's worth, I now have to change module.exports.get_napi_version in node_modules/node-pre-gyp/lib/util/napi.js to return 5 to get it to run (i.e. return 4 no longer works).

The below prints 5 as expected:

var version = process.versions.napi;
console.log(version);

[ksabr]

Hi again @kangyizhang ,

I noticed that printing process.versions from node_modules/node-pre-gyp/lib/util/napi.js shows node: '10.11.0' (whereas node --version gives v12.13.0). 10.11.0 is indeed NAPI v3, so that could explain the error. While trying to track down where 10.11.0 comes from, I noticed that electron-prebuilt-compile@^4.0.0 (see https://github.com/tensorflow/tfjs-examples/blob/master/electron/yarn.lock#L2402) and electron 4.0.0 itself require node 10.11.0: https://electronjs.org/releases/stable?version=4&page=6#4.0.0

It looks like electron-prebuilt-compile hasn't been maintained for a year now. I'm wondering whether this explains my issue, but if it does, I don't see how the code would work for anyone else either 😃

One solution could be to ensure that the tfjs-node bindings are built for the version of node shipped with the electron version used, and not the node version locally installed on the machine. Let me know what you think.

[kangyizhang]

@ksabr I can reproduce what you said. This example is suppose to show users how to use tfjs-node with electron framework, so it's possible that it does not work on all platforms.

On windows, you will need to install a certain version of Node.js which has NAPI v3 and >= v8.12.0 (https://nodejs.org/api/n-api.html#n_api_n_api_version_matrix). You can try with node.js v8.12.0 and it works on my machine.

The message node-pre-gyp info This Node instance does not support builds for N-API version 4 is a warning instead of an error. The error comes from electron tools.

[ksabr]

Hi @kangyizhang ,

Thanks a lot - I have a working solution (installing electron 10.11.0, which is the one shipped with electron 4.0.0 used in the example), so I think we can close this. Hopefully other people running with the same problem on their platforms will be able to find a solution in this thread.

Many thanks again!