Safari 18.4 DevTools freeze when using eval-source-map with large Webpack bundles

[JuliaGmP]

Hi! Just wanted to share something we recently debugged that might help others.

We ran into a problem where Safari 18.4 would completely freeze its DevTools after loading a page using Webpack with devtool: "eval-source-map" and a large JS bundle (~9MB before compression).

✅ Safari 17.6 — works fine
❌ Safari 18.4 — DevTools freeze immediately, no console errors
✅ Switching to source-map or disabling source maps (devtool: false) — fixes the issue

We confirmed it's not related to eval in runtime code — the freeze seems to happen while the DevTools parse the generated source maps, probably due to the use of eval() and inline sources.

Posting this here in case anyone else hits this issue and wastes time debugging.
Also, not sure if Webpack should warn against eval-source-map in large projects for Safari specifically?

Anyway — hope this saves someone a headache (or three) 😭😭😭😭

[alexander-akait]

@JuliaGmP Hello, makes sense to open an issue in Safari bug tracker, eval works fine with any other Safari versions, so I think it is a regression on Safari side...