Seven Mantine entry points were missing from optimizePackageImports while
core/hooks/icons-react were listed. Added all seven, rebuilt, and the client
bundle came out byte-for-byte identical: 482 files, 18050.7 KiB, same largest
chunk, same chunk hashes.
Identical output down to the hashes normally means a cached build, and
turbopackFileSystemCacheForBuild is enabled here, so it got checked rather than
written up as a null result. The Next.js docs are explicit: "This is not needed
when using Turbopack. Turbopack automatically analyzes and optimizes imports
without requiring this configuration." The build banner confirms Turbopack.
So the change is reverted and the existing three-entry list documented as dead
config, kept only as a webpack fallback. This also retires the sub-question of
whether @homarr/ui - the largest barrel at 111 importers - could be optimised
this way: it cannot, and it does not need to be.
Two notes for anyone revisiting: Next 16 with Turbopack prints no size columns in
its route table and emits no app-build-manifest.json, so per-route first-load JS
is unavailable from build output; these numbers are total bytes under
.next/static/chunks.
PHASE2-FINDINGS.md had grown past 1,200 lines mixing server memory, client rendering,
methodology and a long list of rejected experiments, which made it unusable as a
reference. Split under docs/perf/:
README.md headline results and the change-by-change ratio table
SERVER-MEMORY.md what the container's RAM is made of, layer by layer
CLIENT-PERFORMANCE.md dashboard cost in Chrome: DOM, fibers, images, paint
REJECTED.md ideas implemented, measured and abandoned, with numbers
METHODOLOGY.md the tools, and the measurement traps that gave wrong answers
PHASE2-FINDINGS.md is now an index so existing links keep working.
METHODOLOGY.md is the part worth keeping: every wrong number in this investigation came
from an instrument rather than the application, and each trap is written down - snapshots
cannot explain peaks, V8 truncates snapshot strings to ~1 KiB, snapshot objects are not
live handles, measuring without a forced GC measures V8's growth, taking a CDP snapshot
added 134 MiB to the process being measured, per-component React attribution silently
returns nothing on a production build, a fixed port can measure a leftover container, and
a server-side change that moves a client-side metric means the workload changed.
Thomas Camlong