# What changed in oniguruma-to-es

> 4 changes in oniguruma-to-es 4 from its official release notes, upgrade guides and advisories. Each one cited. Sources checked 2026-10-18. HTML: https://unstale.sh/npm/oniguruma-to-es/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## oniguruma-to-es 4

### Fixes and other changes

- Prevents a “Maximum call stack size exceeded” timeout with some edge-case uses of overlapping recursive subroutines. (4.3.6) — [release notes](https://github.com/slevithan/oniguruma-to-es/releases/tag/v4.3.6)
- Makes the error message more accurate and helpful for unclosed character classes that start with unescaped `]`. (4.3.6) — [release notes](https://github.com/slevithan/oniguruma-to-es/releases/tag/v4.3.6)
- Environment tests are no longer replaced with constants when bundled with Rolldown. (4.3.5) — [release notes](https://github.com/slevithan/oniguruma-to-es/releases/tag/v4.3.5)
- Works around partial or incomplete v flag support in mobile QQ. (4.3.4) — [release notes](https://github.com/slevithan/oniguruma-to-es/releases/tag/v4.3.4)