instrumentation-undici does not work when enabled: true is set in the configuration

[enikey87]

What version of OpenTelemetry are you using?

  "dependencies": {
    "@opentelemetry/api": "1.9.0",
    "@opentelemetry/auto-instrumentations-node": "0.49.1",
    "@opentelemetry/sdk-metrics": "1.25.1",
    "@opentelemetry/sdk-node": "0.52.1"
  },

What version of Node are you using?

node -v
v20.16.0

What did you do?

Tried to instrument fetch with Node.js auto-instrumentations with explicitly enabled instrumentation-undici:

import { NodeSDK } from '@opentelemetry/sdk-node'
import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node'
import { ConsoleSpanExporter } from '@opentelemetry/sdk-trace-base'
import { register } from 'module'

const sdk = new NodeSDK({
  traceExporter: new ConsoleSpanExporter(),

  instrumentations: [
    getNodeAutoInstrumentations({
      '@opentelemetry/instrumentation-undici': { enabled: true }
    })
  ]
})

sdk.start()

register('@opentelemetry/instrumentation/hook.mjs', import.meta.url)

What did you expect to see?

Expected to see spans exported to console for node's global fetch().

What did you see instead?

No spans in console.

Additional context

• I put repo that illustrates the issue and workaround here.
• No UndiciInstrumentation is applied because it uses config.enabled for both its internal state and the configuration itself.