Prod SSR HTML links a stylesheet hash that no build artefact contains

[Annoiiyed]

Behaviour

Every page load on https://opake.at logs two errors:

• GET /assets/index-N4vJjP7P.css → 404
• React hydration mismatch (#418) on the stylesheet <link>

The page still renders styled because the client router injects the correct stylesheet (index-BMkwwaKQ.css, 200) after hydration. Impact is one dead request plus a hydration warning per page view — cosmetic today, but the hydration mismatch masks any future real ones.

Evidence

• The SSR HTML's modulepreload hashes all match the deployed image's client assets (all 200), so the serving pod is the current image — only the stylesheet URL diverges.
• The CI build log for the deployed image emits dist/client/assets/index-BMkwwaKQ.css and never produces index-N4vJjP7P.css. The SSR environment does not write assets (ssr.emitAssets defaults to false), so the URL baked into the server router chunk is a hash computed over the SSR pass's own CSS output — which diverged from the client pass.
• Behaviour is identical across both replicas; not a rollout or cache-skew artefact.

Reproduction attempts (all negative)

Local builds resolve the SSR ?url to the client's hash in every variant tried:

Variant	Server ref	Client CSS
isolated linker, node	index-BMkwwaKQ.css	index-BMkwwaKQ.css
--linker=hoisted, node	same	same
--linker=hoisted, bun run --bun	same	same
hoisted + TZ=UTC, no locale	same	same

Client CSS is byte-identical between CI and local (same hash), so the divergence is confined to the SSR pass and only occurs in the containerised build. Remaining suspects: the wasm-bindgen glue generated fresh in the wasm-builder stage feeding the SSR pass's Tailwind candidate scan differently from the client pass, or an environment-specific @tailwindcss/vite SSR behaviour.

Next steps

• Inspect dist/server/assets/router-*.js inside the published image (rg.fr-par.scw.cloud/opake/web:prod-e7fd83f…) to confirm the baked URL, and diff the SSR pass's CSS against the client's in an instrumented CI run.
• Candidate fixes once confirmed: resolve the root stylesheet URL from the client manifest instead of the SSR bundle's own ?url emission, or force the SSR pass to reuse the client CSS output.

[Annoiiyed]

Reopened pending verification on a deployed container build — the mismatch only ever manifested in CI images, so green local builds prove nothing here. Candidate fix is on main (161ba58).

[Annoiiyed]

Negative result: pinning the Tailwind scan root (@import "tailwindcss" source("../"), 161ba58) does not fix it. The rebuilt image's server router chunk is byte-identical to the previous build's (router-B_8Iymik.js, content-hashed) and still links index-N4vJjP7P.css; the build step verifiably re-ran with the change. Two observations worth keeping:

• The SSR-side divergence is deterministic in the container — same wrong hash across independent builds.
• The wrong hash is invariant under changes to index.css itself, so whatever the SSR pass is hashing, it is not (a transform of) the current stylesheet source. That also rules out the Tailwind source-detection explanation from chore: add source() to Tailwind v4 imports to ensure consistent hashing TanStack/router#6459 for this case.

Next step remains inspecting the actual image (or running the Containerfile build with a shell) to see what dist/server/assets/router-*.js embeds and where it comes from.

[Annoiiyed]

Verified fixed on prod (1029828). Root cause: the client pass compiles first and writes dist/; the SSR pass rescans afterwards, and without a .git directory the scanner's ignore heuristics don't skip dist/ — so the SSR pass harvested phantom utility candidates from the freshly written minified bundles (~35 kB of extra daisyui rules such as .diff, .modal, .input!) and its stylesheet hashed differently from the client's. Container-only because local checkouts have .git; invariant under index.css edits because the phantom candidates came from the bundles, not the stylesheet source.

Fix: @source not "../dist" (+ .tanstack) so both passes scan identical sources. In-image diagnostic now shows both passes emitting byte-identical CSS, and the live page loads a single stylesheet with HTTP 200 and no hydration errors. The emitAssets setting and Containerfile diagnostic stay as regression tripwires.