[...]\node_modules\mixin-deep\index.js:30
this[key] = val;
^
TypeError: Cannot set property parent of [object Object] which has only a getter
at Buffer.copy ([...]\node_modules\mixin-deep\index.js:30:15)
at forIn ([...]\node_modules\for-in\index.js:12:12)
at mixinDeep ([...]\node_modules\mixin-deep\index.js:11:7)
at File.copy ([...]\node_modules\mixin-deep\index.js:28:5)
at forIn ([...]\node_modules\for-in\index.js:12:12)
at mixinDeep ([...]\node_modules\mixin-deep\index.js:11:7)
at Object.copy ([...]\node_modules\mixin-deep\index.js:28:5)
...
options = merge({ html: true, breaks: true }, config, options);
(cf.