Keep watch alive after rebuild errors

[fhammerschmidt]

A config or source-layout change that made full rebuild initialization fail caused watch mode to panic and exit. Initialization errors now propagate through the build lock, are reported to the user, and leave the previous watch state available for recovery after a later valid change.

This was very easy to reproduce, just remove the trailing } in a rescript.json while the watcher runs, BOOM!

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-10T09:29:17.215570Z	26da9d5	Draft marked ready

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[pkg-pr-new]

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rescript

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@rescript/belt

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@rescript/darwin-arm64

npm i https://pkg.pr.new/rescript-lang/rescript/@rescript/darwin-arm64@8641

@rescript/darwin-x64

npm i https://pkg.pr.new/rescript-lang/rescript/@rescript/darwin-x64@8641

@rescript/linux-arm64

npm i https://pkg.pr.new/rescript-lang/rescript/@rescript/linux-arm64@8641

@rescript/linux-x64

npm i https://pkg.pr.new/rescript-lang/rescript/@rescript/linux-x64@8641

@rescript/runtime

npm i https://pkg.pr.new/rescript-lang/rescript/@rescript/runtime@8641

@rescript/win32-x64

npm i https://pkg.pr.new/rescript-lang/rescript/@rescript/win32-x64@8641

commit: 3e45f81