Show actual error message when loading plugin fails

[razzius]

When attempting to develop a local plugin, I took https://github.com/zeit/hyperpower as a starting point, and cloned it into my local .hyper_plugins/local. I then added it to my localPlugins, and launched the dev app with yarn run dev, however as I didn't have hyperpower's dependencies installed, it could not be required and it errored.

Confusingly, however, the message was

Plugin "hyperpower" not found: /Users/razzi/forks/hyper/.hyper_plugins/local/hyperpower

which confused me because that directory did exist. Requiring that path, I saw the true error:

$ node
> require('/Users/razzi/forks/hyper/.hyper_plugins/local/hyperpower')
Error: Cannot find module 'lodash.throttle'

After I ran npm install from that directory, the error went away, but since I was confused by the error, I think it'd be helpful to show the actual error rather than handling all MODULE_NOT_FOUND errors with the message "Plugin ... not found."

By applying this update, the true error will be clear:

Plugin error while loading "hyperpower" (/Users/razzi/forks/hyper/.hyper_plugins/local/hyperpower): Cannot find module 'lodash.throttle'

I'm not tied to the wording I used - maintainers feel free to edit.

[linonetwo]

When will this be merged? It's useful for debugging.

[chabou]

Thank you ! really better with your message