[BUG]: Express integration - v5.29.0+ reports incompatible version found when using Express v4

[vernak2539]

Tracer Version(s)

5.29.0

Node.js Version(s)

22.11.0

Bug Report

When upgrading our dd-trace module, when we update to v5.29.0 or higher, we get the following output when debug mode is enabled.

$ DD_TRACE_DEBUG=true DD_TRACE_LOG_FILE=ddtrace_logs.log NODE_ENV=production node --import ./src/node-instrumentation.mjs src/server/index.mjs
Found incompatible integration version: [email protected]

I know that 5.29.0 is the same version that released support for express v5, but I would assume that express v4 is still supported based on the README (as it's based on node version).

Reproduction Code

// ./src/server/node-instrumentation.mjs 

import tracer from 'dd-trace';

tracer.init({
  hostname: process.env.DD_HOST,
  service: 'app',
  debug: process.env.DATADOG_DEBUG_ENABLED === 'true',
});

tracer.use('express')

// ./src/server/index.mjs

import express from 'express';

const app = express()
const port = 3000

app.get('/', (req, res) => {
  res.send('Hello World!')
})

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`)
})

Start command

$ DD_TRACE_DEBUG=true DD_TRACE_LOG_FILE=ddtrace_logs.log NODE_ENV=production node --import ./src/node-instrumentation.mjs src/server/index.mjs

Error Logs

N/A

Tracer Config

tracer.init({
  hostname: process.env.DD_HOST,
  service: 'app',
  debug: process.env.DATADOG_DEBUG_ENABLED === 'true',
});

Operating System

Darwin XXX 24.2.0 Darwin Kernel Version 24.2.0

Bundling

No Bundling

[alexwforsythe]

Also seeing this with [email protected]. express 4.X is listed as fully compatible on the Datadog website docs, while 5.X isn't mentioned, so this warning is surprising.

[vernak2539]

~I'm unsure if the problems I layout below are related to this same issue, but since they've occurred with v5.29.0 and higher, I'll tag on here. If you'd like me to move to a separate issue, please let me know. ~

Update: Created #5111 for the issue formerly detailed in this comment.