[React 19] Need Bring Back _debugSource or Provide an Equivalent for Better Developer Experience

[zthxxx]

Problem

React 19 removed the _debugSource property from Fiber nodes (PR #28265), which has broken critical developer tools that enable "click to open the source from browser" functionality.
This removal directly impacts the workflow of thousands of React developers who rely on these tools for rapid debugging and code navigation.

Affected Ecosystem

The following tools/packages as far as I known are affected by React 19:

• react-dev-inspector
• locatorjs
• code-inspector
• click-to-component
• radon-ide
• vite-plugin-react-click-to-component
• react-inspector
• figment

(see issues of them)

Impact

This change:

1. Degrades React's developer experience compared to frameworks like Vue, where source mapping is a first-class feature
2. Forces developers to abandon established debugging workflows
3. Undermines community-driven tooling that compensates for React's lack of official devtools in this area.
   
   Past issues like [React 19] Reintroduce debugSource in some kind of opt-in way #31981 have attempted to address this problem, but received no response from the React team. Does the core team lack prioritization on this matter?

Critical Questions

1. Why was _debugSource need to be remove? The original PR offers no justification for any user cases improvement.
2. Will React commit to restoring this functionality? either restore _debugSource or a supported API, _debugStack isn’t a viable replacement
3. I known the removal was intentional, what is the recommended path forward for tools requiring source position mapping? _debugStack cannot parse for path on filesystem

Call to Action

We appeal to the React team to:

• Explain the reasoning behind this design
• Either reintroduce _debugSource or provide an equivalent official mechanism for source mapping
• Collaborate with the community to preserve critical debugging workflows

Final

The React community has spent 5+ years in building tools to close DX gaps. Arbitrarily removing internal properties like _debugSource without warning or alternatives undermines community efforts.

Vue developers enjoy seamless click-to-source workflows – why can't React developers have parity?

Thanks in advance!

[zthxxx]

@sebmarkbage @rickhanlonii