RollupError: called `Option::unwrap()` on a `None` value with Rollup >=4.53

[kernoeb]

Rollup Version

4.53.1

Operating System (or Browser)

macOS, browser (wasm)

Link To Reproduction

https://stackblitz.com/edit/rollup-repro-1zwsfca2

(The bug is a bit more opaque on wasm version)

Expected Behaviour

Build should work
It works with rollup 4.52

Actual Behaviour

Here's the error i get when running npm run build (npx rollup index.js --file bundle.js --format esm --plugin @rollup/plugin-node-resolve --plugin @rollup/plugin-commonjs).

I got the issue in my Vite.js project, and found the error was in Rollup, not Vite.

thread '<unnamed>' panicked at <redacted>:0:0:
called `Option::unwrap()` on a `None` value
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[!] RollupError: called `Option::unwrap()` on a `None` value (Note that you need plugins to import files that are not JavaScript)
node_modules/number-flow/dist/lite-BTIaQdTe.mjs
    at Object.getRollupError (/private/tmp/tests/node_modules/rollup/dist/shared/parseAst.js:285:41)

[barbyJam]

We have a same problem, #6175
only diff 2 mins~~~

[barbyJam]

Before the bug is solved, we have only two methods to fix, either double-check the String.raw gramma, changing to normal string, or limiting the version below to the 4.53.

[Arecsu]

second here having this problem, macOS

transforming (812) node_modules/.pnpm/@number-flow+svelte@file+..+..+..+..+..+tmp+number-flow+pa
thread '<unnamed>' panicked at <redacted>:0:0:
called `Option::unwrap()` on a `None` value
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
transforming (927) commonjsHelpers.jscalled `Option::unwrap()` on a `None` value (Note that you need plugins to import files that are not JavaScript)
file: /Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/number-flow@file+..+..+..+..+..+tmp+number-flow+packages+number-flow/node_modules/number-flow/dist/lite-BTIaQdTe.mjs
  Stack trace:
    at getRollupError (file:///Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/rollup@4.53.1/node_modules/rollup/dist/es/shared/parseAst.js:401:41)
    at convertNode (file:///Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/rollup@4.53.1/node_modules/rollup/dist/es/shared/node-entry.js:16343:10)
    at Module.setSource (file:///Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/rollup@4.53.1/node_modules/rollup/dist/es/shared/node-entry.js:17340:24)
  Caused by:
  called `Option::unwrap()` on a `None` value
    at getRollupError (file:///Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/rollup@4.53.1/node_modules/rollup/dist/es/shared/parseAst.js:401:41)
    at convertNode (file:///Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/rollup@4.53.1/node_modules/rollup/dist/es/shared/node-entry.js:16343:10)
    at Module.setSource (file:///Users/arecsu/martyr/martyrio/web/node_modules/.pnpm/rollup@4.53.1/node_modules/rollup/dist/es/shared/node-entry.js:17340:24)
 ELIFECYCLE  Command failed with exit code 1.

[hempun10]

Just ran into this exact issue and wanted to share what worked for me!

What I was seeing:

thread '<unnamed>' panicked... called `Option::unwrap()` on a None value

Build kept failing at node_modules/number-flow/dist/index.mjs even though I'm using the scoped @number-flow/react package. Super frustrating.

My setup:

• Vite 5.4.21
• @number-flow/react 0.4.0
• Node 22.17.1

The fix that actually worked:

Turns out it's a Rollup 4.53.x bug, not Vite or number-flow. Just add this to your package.json:

{
  "overrides": {
    "rollup": "4.52.0"
  }
}

Then:

rm -rf node_modules package-lock.json
npm install

Boom, build succeeded. Back to normal.

Why this works:
Vite uses Rollup under the hood for production builds, and 4.53 introduced a regression in its Rust parser that chokes on number-flow's ES module syntax. Rolling back to 4.52.0 gets you back to the stable JavaScript parser.

Hope this saves someone else a few hours! 😅

[github-actions]

This issue has been resolved via #6177 as part of rollup@4.53.2. You can test it via npm install rollup.