Turbopack ships the framer-motion runtime twice on 46 routes after the platform page removal

[jadhavgaurav]

Symptom

The bundle-budget ratchet fails on development since cb7448bf ("remove the unfinished CleanStart Platform page"): /vulnerability-remediation grew from 317.8 KB to 345.3 KB gzipped (+27.5 KB, tolerance 5 KB). Absolute budgets are warn-only, so only the ratchet blocks.

Cause

Turbopack now emits the framer-motion runtime twice in production. Two chunks (0enzg3fle.a7y.js and 0bhimso_.o1iv.js in the current build) carry the same modules: every marker string (whileInView, onViewportEnter, whileHover, whileTap, layoutId, keyframes, spring, inertia, prefers-reduced-motion) appears with identical counts in both, and sampled content similarity is 0.97.

• One copy is in the global chunk loaded by all 616 routes (via FadeUp in the layout tree).
• The second is in a chunk loaded by 46 marketing routes (the ones using components/ui/Reveal).
• Those 46 routes therefore ship about 25 KB gzipped of duplicated JavaScript.

Attribution

Clean-worktree production builds, counting motion-runtime chunks on /vulnerability-remediation:

Commit	Copies	Route size
0dcb7ce9 last green	1	319.3 KB
e737c0f2 Impact Estimator rename	1	319.3 KB
559a0984 compare page rebuild	1	319.3 KB
d61c7ce0 gauge glyph	1	319.3 KB
cb7448bf platform page removal	2	344.8 KB

cb7448bf touches no motion imports (git diff 0dcb7ce9..HEAD -- apps/web/src | grep motion shows only a moved import line). Removing that route changed the set of routes sharing the motion modules, and Turbopack's chunk grouping responded by duplicating them rather than keeping one shared chunk.

Decision so far

PR #258 was merged past the failing ratchet with this issue as the tracker, rather than re-baselining and hiding the cost.

To resolve

• Work out why Turbopack duplicates the module group after the route removal (chunk-merging heuristic, or two chunk groups both claiming the modules) and whether a config or import-structure change restores one shared chunk.
• Until then the ratchet will fail on every web CI run. If the duplication is accepted, re-baseline with UPDATE_BUNDLE_BASELINE=1 pnpm --filter @cleanstart/web bundle:budget against a production server and say so in the commit.

Repro

NEXT_PUBLIC_CMS_URL=https://cms.cleanstart.com pnpm --filter @cleanstart/web build
cd apps/web && grep -o 'src="[^"]*"' .next/server/app/vulnerability-remediation.html | grep _next | wc -l   # 18, was 17

Then gzip each chunk and grep two of them for whileInView.