Some error at 6.4.0

[likerainyday]

ERROR in ./node_modules/mqtt-packet/node_modules/bl/BufferList.js
Module build failed (from ./node_modules/babel-loader/lib/index.js):
SyntaxError: "copy" is read-only

78 | BufferList.prototype.copy = function copy (dst, dstStart, srcStart, srcEnd) {
| ^
79 | if (typeof srcStart !== 'number' || srcStart < 0) {
80 | srcStart = 0
81 | }

[mcollina]

I don't know what this mean :/.