Internal repro:
./utr.pl --suite=integration --testtarget=iOS --testfilter=Unity.IntegrationTests.CrashReporting.CrashReportingBuildsTest.CanBuildiOS
The test enables CloudDiagnostics and performs a batchmode build. The resultant Xcode project won't compile with the error:
Please provide an auth token with USYM_UPLOAD_AUTH_TOKEN environment variable.

Compiling the Xcode project by passing the env variable to xcodebuild process results in a successful build:
USYM_UPLOAD_AUTH_TOKEN=test xcodebuild build <projectPath>

To reproduce:

1. Download attached "Project.zip" project and open in Unity
2. Change the platform to iOS
3. Enable Cloud Diagnostics
4. Close Unity Editor
5. Build in BatchMode with Arguments:

<Unity Path> -batchmode -buildTarget iOS -runTests -testplatform playmode -projectpath <PATH> -executeMethod BuildScript.UnityBuildTest -username <Your Unity ID> -password <Password of your Unity ID> -quit

6. When Build complete, open Xcode project
7. In Menu bar press Product > Build

Expected result: Xcode successfully Builds Project
Actual result: Xcode fails to Build Project and throws Error:

"Please provide an auth token with USYM_UPLOAD_AUTH_TOKEN environment variable"

Notes:
- This issue happens only on iOS
- If You Build directly from Unity Editor, everything works as Expected
- If You Build without "-runTests -testplatform playmode" or with Cloud Diagnostics disabled, the Build in Xcode completes without any issues
- The Project and a Video how to reproduce this issue are attached in Comments section
- There are few Forum links to this issue:
https://forum.unity.com/threads/ios-build-issues-should-be-resolved-and-unity-2019-1-4f1-now-available.687163/
https://forum.unity.com/threads/unity-2018-4-1f1-lts-batch-build-for-ios-is-not-working.690103/
https://forum.unity.com/threads/unity-2018-4-1f1-lts-batchmode-for-ios-is-not-working.693010/

Reproduced on Unity 2018.4.1f1, 2018.4.3f1, 2019.1.9f1, 2019.2.0b8 and 2019.3.0a8
Not reproduced on Unity 2018.4.0f1
Regression on Unity 2018.4.1f1