build script fails with syntax errors in `gatsby-plugin-mdx` after upgrade to 3.0.8

I upgraded from 1.7.x to 3.0.8, and am unable to build. I reviewed the upgrading document, and fixed a number of issues listed there, but unfortunately can’t see a match between this error and any of the listed things to do when upgrading.

Anybody else have this issue? Could easily be user error but mdx-deck is the only thing I use MDX for and don’t readily see the boundary between what it is responsible for, and its dependencies.

i have an error output like this:

yarn run build
yarn run v1.17.3
$ mdx-deck build deck.mdx
info Deleting .cache, public
info Successfully deleted directories

success open and validate gatsby-configs - 0.035 s
success load plugins - 0.279 s
success onPreInit - 0.013 s
success delete html and css files from previous builds - 0.014 s
success initialize cache - 0.017 s
success copy gatsby files - 0.037 s
success onPreBootstrap - 0.020 s
success source and transform nodes - 0.518 s
success building schema - 0.156 s
success createPages - 0.168 s
success createPagesStatefully - 0.021 s
success onPreExtractQueries - 0.010 s
success update schema - 0.038 s
success extract queries from components - 0.100 s
success write out requires - 0.014 s
success write out redirect data - 0.011 s
success onPostBootstrap - 0.013 s
⠀
info bootstrap finished - 2.787 s
⠀
success run static queries - 0.013 s
success Building production JavaScript and CSS bundles - 7.862 s
success Rewriting compilation hashes - 0.017 s
success run page queries - 0.038 s — 2/2 124.17 queries/second

 ERROR #95313

Building static HTML failed for path "/"

See our docs page for more info on this error: https://gatsby.dev/debug-html


  29 |       const keys = Object.keys(fullScope);
  30 |       const values = keys.map(key => fullScope[key]);
> 31 |       const fn = new Function("_fn", ...keys, `${children}`);
     |               ^
  32 |
  33 |       return fn({}, ...values);
  34 |     },


  WebpackError: SyntaxError: Unexpected token export

  - mdx-renderer.js:31
    gatsby-plugin-mdx/mdx-renderer.js:31:15

  - mdx-renderer.js:15 MDXRenderer
    gatsby-plugin-mdx/mdx-renderer.js:15:15


⠇ Building static HTML for pages
(node:71658) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
Error: Command failed with exit code 1 (EPERM): gatsby build
    at makeError (/Users/eve/workspace/decks/algorand-primer/node_modules/mdx-deck/node_modules/execa/lib/error.js:58:11)
    at handlePromise (/Users/eve/workspace/decks/algorand-primer/node_modules/mdx-deck/node_modules/execa/index.js:112:26)
    at processTicksAndRejections (internal/process/task_queues.js:85:5)
error Command failed with exit code 1.

unfortunately I am not so familiar with Webpack. if this is not appropriate issue here please let me know and I can direct my efforts elsewhere.

thank you very much!

[mattiash]

Thanks @michaellopez for the workaround. I can confirm that it works for me.

[mattiash]

I think I have the same problem. I have built a small sample presentation to show the problem:

https://github.com/mattiash/presentation

I am trying to use a custom theme. Without the line

export { theme } from './theme.js'

in deck.mdx it builds fine, but with this line npm run build fails with

WebpackError: SyntaxError: Unexpected token export