fix(miniflare): handle missing require.cache in getFreshSourceMapSupport (fix dev server crash under Yarn PnP)#13968
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NuroDev merged 2 commits intoMay 28, 2026
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When `miniflare` is imported from ESM under Yarn PnP, Node's ESM->CJS bridge (`loadCJSModule` in `node:internal/modules/esm/translators`) hands the wrapped CJS module a re-invented `require` that only carries `.resolve` and `.main`, with no `.cache`. The cache-swap below needs a real CJS cache, so fall back to one built via `createRequire(__filename)` when we detect the stub. No behavior change on the normal CJS-loaded path. Fixes a `TypeError: Cannot read properties of undefined (reading '<path>')` crash in `wrangler dev` whenever the worker emits a structured log or the inspector forwards a stack trace, on Yarn PnP setups using Node 22-24.
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create-cloudflare
@cloudflare/deploy-helpers
@cloudflare/kv-asset-handler
miniflare
@cloudflare/pages-shared
@cloudflare/unenv-preset
@cloudflare/vite-plugin
@cloudflare/vitest-pool-workers
@cloudflare/workers-editor-shared
@cloudflare/workers-utils
wrangler
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🦋 Changeset detectedLatest commit: 5f81952 The changes in this PR will be included in the next version bump. This PR includes changesets to release 5 packages
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Thanks for this change @danieltroger 🧡
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Hits Yarn PnP setups using
wrangler devon Node 22 through 24. As soon as the worker emits a structured log or the inspector forwards a stack trace, wrangler crashes:require.cacheisundefinedat the failing line.Why: wrangler does
import "miniflare", Node's ESM loader asks Yarn PnP's loader hook for the source ofminiflare/dist/src/index.js, gets it back, and therefore routes throughloadCJSModuleinnode:internal/modules/esm/translatorsinstead ofloadCJSModuleWithModuleLoad. The Node translator path used when a hook returns asourcehands the wrapped CJS code a re-inventedrequirethat only carries.resolveand.main, no.cache. Confirmed by loggingObject.keys(require)->[ 'resolve', 'main' ]andString(require).slice(0, 200)-> the body ofloadCJSModule'srequireFn.Fix: when we detect the stub (no
.cache), reach for a real CJS require viacreateRequire(__filename)for the cache-swap dance. No behavior change on the normal CJS-loaded path.Related: yarnpkg/berry#7065 is the adjacent Node 25.7+
EBADFregression in the same area, but this symptom is independent and reproduces on Node 22 through 24.Repro
Node 24.15.0, Yarn 4.14.1 with
.yarnrc.ymlcontainingnodeLinker: pnp,wrangler@4.88.0/miniflare@4.20260504.0, plus anything that makes the worker emit a structured log:yarn patch, the crash is gone (0xTypeError) and worker stack traces source-map normally.