Exit the process on successful download case

[glemercier]

When I use the following install command in package.json as recommended in the documentation:

...
  "scripts": {
    "install": "prebuild-install || node-gyp rebuild"
  }
...

The prebuilt binary is properly downloaded, installed, but after that the installation process never returns. Is that expected? If not, would this patch be an acceptable fix?

[vweevers]

Sounds like there's something keeping the node process open. If so, doing process.exit(0) would hide a bug.

wtfnode can help to find open handles.

[glemercier]

Here is what I get with wtfnode:

# wtfnode /usr/local/bin/npm install artik-sdk

> artik-sdk@1.6.1 install /root/node_modules/artik-sdk
> prebuild-install || node-gyp rebuild

prebuild-install info begin Prebuild-install version 2.3.0
prebuild-install info looking for local prebuild @ prebuilds/artik-sdk-v1.6.1-node-v48-linux-arm64.tar.gz
prebuild-install info looking for cached prebuild @ /root/.npm/_prebuilds/https-github.com-SamsungARTIK-artik-sdk-js-releases-download-v1.6.1-artik-sdk-v1.6.1-node-v48-linux-arm64.tar.gz
prebuild-install info found cached prebuild
prebuild-install info unpacking @ /root/.npm/_prebuilds/https-github.com-SamsungARTIK-artik-sdk-js-releases-download-v1.6.1-artik-sdk-v1.6.1-node-v48-linux-arm64.tar.gz
prebuild-install info unpack resolved to /root/node_modules/artik-sdk/build/Release/artik-sdk.node
prebuild-install info unpack required /root/node_modules/artik-sdk/build/Release/artik-sdk.node successfully
prebuild-install info install Successfully installed prebuilt binary!
^C[WTF Node?] open handles:
- File descriptors: (note: stdio always exists)
  - fd 1 (tty) (stdio)
  - fd 2 (tty) (stdio)
- Child processes
  - PID 366
    - Entry point: /usr/lib/node_modules/npm/lib/utils/spawn.js:21

Note sure what's wrong or if npm is to be blamed here. Note that I'm running on an ARM64 platform running Ubuntu 16.04 and here are is my setup in case it's relevant:

# node -v
v6.11.3
# npm -v
3.10.10

[glemercier]

Same thing after upgrading to npm 5.5.1.

#npm -v
5.5.1
# wtfnode /usr/local/bin/npm install artik-sdk
...
prebuild-install info install Successfully installed prebuilt binary!
^C[WTF Node?] open handles:
- File descriptors: (note: stdio always exists)
  - fd 1 (tty) (stdio)
  - fd 2 (tty) (stdio)
- Child processes
  - PID 442
    - Entry point: /usr/local/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:36

/usr/local/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js

const _spawn = require('child_process').spawn
const EventEmitter = require('events').EventEmitter

let progressEnabled
let running = 0

function startRunning (log) {
  if (progressEnabled == null) progressEnabled = log.progressEnabled
  if (progressEnabled) log.disableProgress()
  ++running
}

function stopRunning (log) {
  --running
  if (progressEnabled && running === 0) log.enableProgress()
}

function willCmdOutput (stdio) {
  if (stdio === 'inherit') return true
  if (!Array.isArray(stdio)) return false
  for (let fh = 1; fh <= 2; ++fh) {
    if (stdio[fh] === 'inherit') return true
    if (stdio[fh] === 1 || stdio[fh] === 2) return true
  }
  return false
}

function spawn (cmd, args, options, log) {
  const cmdWillOutput = willCmdOutput(options && options.stdio)

  if (cmdWillOutput) startRunning(log)
  const raw = _spawn(cmd, args, options) =======================> line 36
  const cooked = new EventEmitter()

[vweevers]

Might be more telling to use the programmatic API of wtfnode, so that it prints the handles of the process that's running prebuild-install.

Try adding it to prebuild-install/bin.js, with a require statement at the top and a dump() at the end:

#!/usr/bin/env node
var wtf = require('wtfnode')

// ..

log.info('install', 'Successfully installed prebuilt binary!')
wtf.dump()

[vweevers]

Oh, could it be that your native module opens a handle / starts a timer / etc? Because prebuild-install does require('/path/to/artik-sdk.node') to test it, and this is the last step.

[glemercier]

Did not get more info, actually less:

prebuild-install info install Successfully installed prebuilt binary!
[WTF Node?] open handles:
- File descriptors: (note: stdio always exists)
  - fd 1 (tty) (stdio)
  - fd 2 (tty) (stdio)

You're right about the test step, there are a lot of things going on when you require the "artik-sdk" module. Is there a way to bypass this verification step? Otherwise I'll look at ways to fix it in the addon.

[vweevers]

Did not get more info, actually less.

That makes sense if the native module is the culprit.

Is there a way to bypass this verification step?

@ralphtheninja?

[ralphtheninja]

Is there a way to bypass this verification step?

Nope, not at the moment. This sounds like a bug in the native node module, no module should lock if only required.

[glemercier]

Makes sense, I'll go ahead and fix the native module. Thanks a lot guys for the quick support, closing the PR now.