Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

WebdriverIO Version

9.3.1

Node.js Version

v18.20.4

Mode

WDIO Testrunner

Which capabilities are you using?

{
  "capabilities": {
    "alwaysMatch": {
      "platformName": "iOS",
      "appium:deviceName": "iPhone(?! 11).*$",
      "appium:platformVersion": "1[678]",
      "wdio:specs": [
        "../../src/tests/all/**/*.test.ts"
      ],
      "bstack:options": {
        "resignApp": false,
        "projectName": "REDACTED",
        "buildName": "REDACTED",
        "sessionName": "REDACTED",
        "debug": true,
        "networkLogs": false,
        "interactiveDebugging": false,
        "appiumLogs": false,
        "maskCommands": "setValues, getValues, setCookies, getCookies",
        "wdioService": "9.3.0"
      },
      "appium:settings[snapshotMaxDepth]": 62,
      "appium:settings[customSnapshotTimeout]": 0,
      "appium:locale": "en_US",
      "appium:app": "REDACTED"
    },
    "firstMatch": [
      {}
    ]
  }
}

What happened?

When starting our wdio run, we sometimes have an error on the session init when calling https://hub-cloud.browserstack.com/wd/hub/session with the error below.
Right now, we are having difficulty pinpointing why, and the output [object Object] makes it more difficult to understand.

The output [object Object] format issue came from this line of code when err is an object. I suspect doing a JSON.stringify when it is an object helps figure out the content of our object in the below error stack case.

00:10:54.037  [0-19] 2025-05-05T05:20:54.058Z ERROR webdriver: Error: WebDriverError: Failed to fetch https://hub-cloud.browserstack.com/wd/hub/session: [object Object] when running "https://hub-cloud.browserstack.com/wd/hub/session" with method "POST" and args "REDACTED"
00:10:54.037  [0-19]     at FetchRequest._libRequest (REDACTED/node_modules/webdriver/build/index.js:1474:15)
00:10:54.037  [0-19]     at FetchRequest._request (REDACTED/node_modules/webdriver/build/index.js:1381:20)
00:10:54.037  [0-19]     at startWebDriverSession (REDACTED/node_modules/webdriver/build/index.js:901:16)
00:10:54.037  [0-19]     at Function.newSession (REDACTED/node_modules/webdriver/build/index.js:1625:41)
00:10:54.038  [0-19]     at remote (REDACTED/node_modules/webdriverio/build/index.js:7736:20)

Note that I found the following similar case. We also suspect the root cause of the problem to be related to BrowserStack. We just need a better error output to have better clues about why it is happening.

• [🐛 Bug]: WebdriverIO fails making session requests to cloud vendors with long response times #13425
• [🐛 Bug]: Cannot run iOS specs on Browserstack after upgrade to wdio v9 #13477

What is your expected behavior?

Expected the error to output the content of [object Object]

How to reproduce the bug.

There are no clear steps to reproduce; this error is hard to encounter, occurring around 3-5 times per run of 300 tests.

Relevant log output

00:10:54.037  [0-19] 2025-05-05T05:20:54.058Z ERROR webdriver: Error: WebDriverError: Failed to fetch https://hub-cloud.browserstack.com/wd/hub/session: [object Object] when running "https://hub-cloud.browserstack.com/wd/hub/session"

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Is there an existing issue for this?

• I have searched the existing issues