failed to add a project using mdx-deck into an existing monorepos

[John King]

Hi,

Starting a new project with the instructions of Mdx-deck README.md works fine, but failed to add it into an existing monorepos in which I am also using Gatsby + mdx + theme-ui.

here is the error message

Uncaught TypeError: __webpack_require__(...) is not a function
    at Object../node_modules/core-js/modules/es6.array.iterator.js (es6.array.iterator.js:11)
    at __webpack_require__ (bootstrap:789)
    at fn (bootstrap:100)
    at Object.<anonymous> (web.dom.iterable.js:1)
    at Object../node_modules/core-js/modules/web.dom.iterable.js (web.dom.iterable.js:51)
    at __webpack_require__ (bootstrap:789)
    at fn (bootstrap:100)
    at Object.<anonymous> (_iter-define.js:2)
    at Object../node_modules/core-js/modules/_iter-define.js (_iter-define.js:16)
    at __webpack_require__ (bootstrap:789)
./node_modules/core-js/modules/es6.array.iterator.js @ es6.array.iterator.js:11
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
(anonymous) @ web.dom.iterable.js:1
./node_modules/core-js/modules/web.dom.iterable.js @ web.dom.iterable.js:51
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
(anonymous) @ _iter-define.js:2
./node_modules/core-js/modules/_iter-define.js @ _iter-define.js:16
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
(anonymous) @ es6.string.iterator.js:5
./node_modules/core-js/modules/es6.string.iterator.js @ es6.string.iterator.js:2
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
(anonymous) @ _iter-define.js:16
./node_modules/core-js/modules/_iter-detect.js @ _iter-detect.js:5
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
(anonymous) @ es6.promise.js:243
./node_modules/core-js/modules/es6.promise.js @ es6.promise.js:142
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
(anonymous) @ api-runner-browser.js:7
./.cache/app.js @ app.js:16
__webpack_require__ @ bootstrap:789
fn @ bootstrap:100
0 @ index.js:7
__webpack_require__ @ bootstrap:789
(anonymous) @ bootstrap:856
(anonymous) @ bootstrap:856
client.js?path=/__webpack_hmr&reload=true&overlay=false:95 [HMR] conne