wrapFetchWithSentry rewrites the HTML response stream chunk-by-chunk to inject trace meta tags. The quote-scanning path in addMetaTagToHead is not sound across chunk boundaries, and a partner integration hit a build-breaking TanStack prerender failure that is separate from the already-fixed React #418 newline issue.
Reported by a Cloudflare + TanStack Start partner integration. Observed on @sentry/cloudflare / related stack at 10.56.0. The reporter confirmed the React hydration #418 half matches #21915 (fixed in 10.64.0); this tracks the remaining stream-transform failure.
Verified
- On current
develop, packages/tanstackstart-react/src/server/wrapFetchWithSentry.ts still processes each decoded chunk independently with:
// Skip quoted attribute values so we don't match <head> inside e.g. data-code="...<head>..."returnhtmlChunk.replace(/"[^"]*"|'[^']*'|(<head>)/g, ...)
- The same file still documents an optimistic assumption that HTML chunks will not split inside
<head>; if they do, injection is skipped rather than carried across chunks. - Related closed issues do not cover this failure mode:
Reported symptoms
- TanStack SSR stream transform threw
SSR stream tail exceeded maximum buffer during prerender and failed the build - Failure was timing/chunk-boundary dependent: passed locally, failed in CI
- Partner hypothesis (medium confidence): a chunk boundary inside a quoted attribute value can desynchronize the per-chunk quote scan and misparse markup, independent of the newline fix
Workaround
Unknown
- Exact TanStack Start / React versions in the failing app
- Minimal public reproduction
- Whether the buffer error is caused only by quote-scan desync, by
<head> split across chunks, by interaction with TanStack prerender buffering, or a combination
Requested by Nicolas Hrubec.
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View Junior Session[Sentry]
wrapFetchWithSentryrewrites the HTML response stream chunk-by-chunk to inject trace meta tags. The quote-scanning path inaddMetaTagToHeadis not sound across chunk boundaries, and a partner integration hit a build-breaking TanStack prerender failure that is separate from the already-fixed React #418 newline issue.Reported by a Cloudflare + TanStack Start partner integration. Observed on
@sentry/cloudflare/ related stack at10.56.0. The reporter confirmed the React hydration #418 half matches #21915 (fixed in10.64.0); this tracks the remaining stream-transform failure.Verified
develop,packages/tanstackstart-react/src/server/wrapFetchWithSentry.tsstill processes each decoded chunk independently with:<head>; if they do, injection is skipped rather than carried across chunks.getTraceMetaTagscaused React Why can't I catch an error directly after install() ? #418 (fixed in10.64.0via fix(core): Print getTraceMetaTags in 1 line to prevent hydration errors #22004)injectTraceMetaTagscorrupts multi-byte UTF-8 split across SSR stream chunks (React hydration error #418) #23305 — UTF-8 multi-byte characters corrupted across stream chunks in React Router injectorsReported symptoms
SSR stream tail exceeded maximum bufferduring prerender and failed the buildWorkaround
wrapFetchWithSentrywhen tracing is not needed (tracesSampleRate: 0); middleware-only setup was sufficient for the reporter>=10.64.0for the separate Why can't I catch an error directly after install() ? #418 newline fix, then re-test the wrapper if tracing is enabledUnknown
<head>split across chunks, by interaction with TanStack prerender buffering, or a combinationRequested by Nicolas Hrubec.
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View Junior Session[Sentry]