Regression in 5.112.0: Self-reference dependency has unused export name for CommonJS modules #22788

Have you used AI?

Yes

Which part of webpack is affected?

not sure

Bug Description

Since webpack 5.112.0, production builds crash during bundle generation when side-effect-free CommonJS modules read their own exports inside functions. This is the same internal error as #21619. That issue's reproduction still builds on 5.112.0, but this package graph fails on 5.112.0 and builds on 5.111.1.

The error occurs with production usedExports optimization:

Self-reference dependency has unused export name: This should not happen

The failure was found in an application that reaches viem's CommonJS build through wagmi / @safe-global/safe-apps-sdk. The reproduction reduces this to a single require('viem').

Link to Minimal Reproduction and steps to reproduce

https://stackblitz.com/edit/webpack-self-reference-repro-1cmzhfxh?file=README.md

Steps:

1. Run pnpm install.
2. Run pnpm run build.
3. See 8 errors from @noble/curves, @scure/base, @scure/bip32 and ox/_cjs.

Optionally, run pnpm run build:without-tree-shaking and see how it succeeds. Pinning webpack to 5.111.1 also succeeds.

Expected Behavior

Webpack should tree-shake or retain the self-referenced exports and complete the build, as it does on 5.111.1.

Actual Behavior

Webpack aborts during bundle generation:

ERROR in ./node_modules/.pnpm/@noble+curves@1.9.7/node_modules/@noble/curves/abstract/hash-to-curve.js
Self-reference dependency has unused export name: This should not happen

ERROR in ./node_modules/.pnpm/@noble+curves@1.9.7/node_modules/@noble/curves/abstract/weierstrass.js
ERROR in ./node_modules/.pnpm/@noble+curves@1.9.7/node_modules/@noble/curves/secp256k1.js
ERROR in ./node_modules/.pnpm/@scure+base@1.2.6/node_modules/@scure/base/lib/index.js
ERROR in ./node_modules/.pnpm/@scure+bip32@1.7.0/node_modules/@scure/bip32/lib/index.js
ERROR in ./node_modules/.pnpm/ox@0.14.56/node_modules/ox/_cjs/core/Secp256k1.js
ERROR in ./node_modules/.pnpm/ox@0.14.56/node_modules/ox/_cjs/erc6492/SignatureErc6492.js
ERROR in ./node_modules/.pnpm/ox@0.14.56/node_modules/ox/_cjs/erc8010/SignatureErc8010.js

webpack 5.112.0 compiled with 8 errors

Running pnpm run build:without-tree-shaking succeeds.

Environment

System:
  OS: macOS 26.7.1
  CPU: (10) arm64 Apple M1 Max
  Memory: 32.00 GB
Binaries:
  Node: 22.22.2
  pnpm: 10.33.0
Packages:
  webpack: 5.112.0 => 5.112.0
  webpack-cli: 6.0.1 => 6.0.1
  viem: 2.57.7 (ox 0.14.56, @noble/curves 1.9.7)

Is this a regression?

Yes (please specify version below)

Last Working Version

5.111.1

Additional Context

Requiring @noble/curves/secp256k1 directly does not trigger the error. It only appears when these modules are reached through the viem → ox CommonJS graph, so I have not yet reduced it to plain source files.

Likely related to #21619, #13983 and #18315. This case does not use workers or usedExports: "global".

AI assistance was used to organize this report. I reviewed the reproduction, commands, and technical details.