TypeError: options.customExtensions is not iterable

[BobNobrain]

At build function, when using with options:

build(
    'TeX',
    'AsciiMath',
    'CommonHTML', {
        toFile: true,
        compress: true,
        folder: 'ascii'
    }
);

It fails because you try to ...options.customExtensions, but it's undefined. I suppose you meant options to be written above default options object, but it's not made. So use smth like options = Object.assign({}, defaultOptions, options); (it solved issue on my side)

[pkra]

Thanks for the report.