Rspack 2.2.8: resolver cache, memory shrinks, modern-module deferral (28 Sep 2026)

No affiliate links. This is a frontend toolchain note from the Rspack GitHub releases, the npm @rspack/core registry, and the Announcing Rspack 2.2 blog. ShopperCove has not upgraded a production bundler to 2.2.8 for this article.

Why 2.2.8 now

npm @rspack/core@2.2.8 is the latest dist-tag as of 5 Oct 2026, published 28 Sep 2026 (14:37 UTC / 20:07 IST). The GitHub release v2.2.8 landed at 14:55 UTC the same day. Among Bun (1.4.2, 5 Sep), Prettier (3.9.9, 23 Sep), and @rspack/core (2.2.8, 28 Sep)—with Vite 8.3.2 and Turborepo 2.11.7 already packaged earlier today—this is the freshest Rspack stable line for the Bun/Prettier/Rspack slot.

2.2.8 is a dense patch on the 2.2 line announced 26 Aug 2026 (compact-hashed IDs, HMR CSS skip, Baseline browserslist, more Linux targets). The operator story here is the resolver cache, memory footprint work, and a handful of correctness fixes—not a new major.

What 2.2.8 changes

From the v2.2.8 release and compare v2.2.7…v2.2.8:

Features that stayed

1. Resolver cache in the new cache system (#15839) — resolve results participate in the newer cache path. Expect fewer repeated resolve walks on warm rebuilds once you are on persistent/new cache settings (cache config).

Features that did not ship

2. JavaScript URL entries with factory-type probes landed as #15666 and were reverted in the same release (#15840). Do not plan upgrades around that entry behavior for 2.2.8.

Performance (memory / retained capacity)

Multiple core shrinks: box optional match-resource / RSC / import-attribute data; store binding refs as indices; reuse compilation dependency arrays; shrink dependency location storage; box module-request strings; reduce retained dependency/source capacity; share used-by-exports payloads; skip unused code-splitting cache copies; release stats handles per module while converting stats to JS (PRs #15831, #15821, #15837, #15834, #15763, #15844, #15849, #15856, #15854, #15851, #15867, #15788).

Fixes worth the pin

• Preserve deferred evaluation in modern-module output (#15846)
• Resolve relative tsconfig paths against cwd (#15713)
• Interrupt compaction at cache shutdown (#15850); reset MultiCompiler done state on watch restart (#15865)
• Require a name for shared dependency tree shaking (#15872); allow unnamed Module Federation consumers in types (#15868)
• CLI: enable compile cache before loading CLI (#15903); respect CI=false and skip compile cache in CI (#15904)
• Loaders: avoid mutating lightningcss-loader options (#15900); normalize builtin options for inline requests (#15909)
• Docs: clarify externals usage (#15866) — see also externals config

Context from the 2.2 line (if you are still on 2.1.x)

The Announcing Rspack 2.2 post (26 Aug 2026) is still the feature baseline: ~5% production-build speedups in their bench, faster CopyRspackPlugin, CSS parse ~3×, HMR that skips unnecessary CSS requests, compact-hashed module/chunk IDs, import.meta.rspackPublicPath, Baseline browserslist targets, and extra Linux native bindings (riscv64 / ppc64 / s390x). Wasm SWC plugins need SWC 77 rebuilds after the 2.2 swc_core bump. Upgrade notes: Upgrading from v1 to v2.

Upgrade checklist

1. Pin exactly: npm i -D @rspack/core@2.2.8 (and matching @rspack/cli / binding packages your stack expects) and commit the lockfile.
2. If you use persistent / new cache: compare cold vs warm resolve times after #15839.
3. If you generate modern-module output: re-test deferred evaluation paths (#15846).
4. If tsconfig paths are relative: confirm resolve-from-cwd behavior (#15713).
5. If you use SWC Wasm plugins from before 2.2: rebuild against SWC 77 (2.2 breaking note)—2.2.8 does not undo that.
6. Do not expect JavaScript URL entry factory probes; they were reverted (#15840).
7. No urgency invented: this is a memory/correctness patch on an already-shipped 2.2 line, not a security advisory of its own.

ShopperCove did not change production Rspack versions for this article. Prefer rspack.rs and the GitHub releases over third-party roundups.

Bottom line

Rspack 2.2.8 (28 Sep 2026) is the patch to take for resolver caching on the new cache path and a stack of memory footprint reductions, plus modern-module deferral and relative-tsconfig fixes. Skip any plan that depended on the briefly-merged JS URL entry probes—they were reverted in the same tag. No affiliate.

Sources

• 01registry.npmjs.org/@rspack/core/2.2.8
• 02rspack.rs/guide/migration/rspack_1.x

Related

• 01shoppercove.com/blog/vite-8-3-2-renderbuilturl-bundled-dev-sourcemaps-october-2026
• 02shoppercove.com/blog/turborepo-2-11-7-sdkroot-oidc-cache-october-2026
• 03shoppercove.com/blog/vite-plus-1-0-unified-toolchain-october-2026
• 04shoppercove.com/blog/webpack-5-111-esm-output-stable-september-2026
• 05shoppercove.com/blog/pnpm-12-9-1-rust-rewrite-wasm-split-october-2026
• 06shoppercove.com/blog/biome-2-5-15-type-inference-nursery-rules-october-2026
• 07shoppercove.com/blog/oxlint-1-87-react-suggestions-a11y-fixes-october-2026
• 08shoppercove.com/blog/eslint-10-12-release-october-2026