Installing from github can create a C++/JS mismatch because of prebuilds

[lilyissillyyy]

Issue or Feature

Trying to call loadImage results in a TypeError (run with a Discord bot's eval command):

TypeError: Cannot read property 'call' of undefined
     at setSource (/root/xiao/node_modules/canvas/lib/image.js:102:14)
     at Image.set (/root/xiao/node_modules/canvas/lib/image.js:65:9)
     at Promise (/root/xiao/node_modules/canvas/index.js:34:15)
     at new Promise (<anonymous>)
     at loadImage (/root/xiao/node_modules/canvas/index.js:23:10)
     at eval (eval at run (/root/xiao/node_modules/discord.js-commando/src/commands/util/eval.js:57:22), <anonymous>:2:1)
     at EvalCommand.run (/root/xiao/node_modules/discord.js-commando/src/commands/util/eval.js:57:22)
     at CommandoMessage.run (/root/xiao/node_modules/discord.js-commando/src/extensions/message.js:214:34)

This does not happen until 1046abf, using 5301420 works as expected.

Steps to Reproduce

const { loadImage } = require('canvas');
loadImage(<Buffer or path>);

Your Environment

• Version of node-canvas (e.g. 1.4.0): 1046abf
• Environment (e.g. node 4.2.0 on Mac OS X 10.8): Ubuntu 18.04.1

[zbjornson]

I can't reproduce this using a local file path or a Buffer, and there's heavy usage of loadImage in the test suite. Do you have more info?

[lilyissillyyy]

https://github.com/dragonfire535/xiao/tree/master/commands/image-edit none of the commands in this collection here that use loadImage work, all throw the error seen above on the latest commit.

[zbjornson]

No release has been made with 1046abf yet, so I assume you're installing from github? Did you rebuild the module?

[lilyissillyyy]

I am installing from github, and yes at first, but the prebuild installed after, and still doesn't work.

[zbjornson]

^ Did you rebuild after pulling? There was a change in the C++ code in that commit, which requires rebuilding the module.

[lilyissillyyy]

It works when providing --build-from-source to the install, so that's likely the reason. The prebuild, however, is currently broken.

[zbjornson]

Ah, node-pre-gyp will fetch the latest prebuild, which in this case creates a mismatch between the JS and C++. That should be fixable from the install script, but you found the workaround (--build-from-source).

(Heads-up, I'm going to change this issue's title to reflect that.)

[LinusU]

Should be fixed in 2.2.0 🚀