[Bug]: width 3 given for non-narrow character error when building certain libraries

[markmssd]

System Info

System:
OS: macOS 15.2
CPU: (10) arm64 Apple M1 Max
Memory: 211.67 MB / 32.00 GB
Shell: 5.9 - /bin/zsh
Binaries:
Node: 20.17.0 - ~/.nvm/versions/node/v20.17.0/bin/node
npm: 10.8.2 - ~/.nvm/versions/node/v20.17.0/bin/npm
pnpm: 7.28.0 - ~/Library/pnpm/pnpm
bun: 1.1.8 - ~/.bun/bin/bun
Browsers:
Brave Browser: 126.1.67.123
Chrome: 131.0.6778.265
Edge: 132.0.2957.115
Safari: 18.2
npmPackages:
@rspack/cli: ^1.1.8 => 1.2.0
@rspack/core: ^1.1.8 => 1.2.0

Details

When using the https://www.npmjs.com/package/@shopify/polaris-viz package, Rspack fails only when mode=production and devtool=source-map (see here).

I still couldn't figure out why it's happening (it wasn't happening with Rspack v1.1.8).

There's a somehow related issue with Rollup: rollup/rollup#5672. The error also seems to come from swc_common, and their fix seems to simply upgrade some unicode-related crates?

I created a repro in which I install this library, and import it in render.js.

Reproduce link

https://github.com/markmssd/rspack-repro/tree/rspack-1.2-error

Reproduce Steps

To reproduce:

git clone https://github.com/markmssd/rspack-repro/tree/rspack-1.2-error
npm i
npm run build:rspack

It will fail with

> [email protected] build:rspack
> cross-env RSPACK=1 rspack

Panic occurred at runtime. Please file an issue on GitHub with the backtrace below: https://github.com/web-infra-dev/rspack/issues
Message:  width 3 given for non-narrow character
Location: index.crates.io-6f17d22bba15001f/swc_common-5.0.0/src/syntax_pos.rs:714

Backtrace omitted.

Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.

[markmssd]

I've tried with v1.2.2 too and the issue still persists.

[markmssd]

I was able to narrow it down (and updated the reproducible) to the single character that's causing the issue.

In that @shopify/polaris-viz repo, there is this file: https://github.com/Shopify/polaris-viz/blob/main/packages/polaris-viz/src/data/character-widths.json, which contains tens of thousands of lines with all characters and their width. Only one of them causes an issue, which is ៘.

FWIW, it has started failing since v1.2.0-alpha.0.

This character makes the build fail, even if it's in the file as a comment. Hopefully this will help fix the issue! (cc @GiveMe-A-Name since you got assigned to it 😄)

[GiveMe-A-Name]

It seems a bug in swc. More detail follow swc-project/swc#10010