jsonazure-devopsazure-pipelines-release-pipelinevstest.console.exe

Azure Devops cscript error - Unexpected end of JSON input

I'm currently setting up an automated UI-test pipeline for a client. The pipeline itself is working (Selenium tests are running and ending accordingly), but at the start of the vstest task, the following error shows in the release:

CScript error - Unexpected end of JSON input

The log itself is only slightly more informative:

2018-11-08T09:01:27.5866296Z VisualStudio version selected for test execution : latest
2018-11-08T09:01:27.7436467Z ========================================================
2018-11-08T09:01:27.7481019Z ======================================================
2018-11-08T09:01:27.7896471Z [command]"C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE\CommonExtensions\Microsoft\TestWindow\vstest.console.exe" @C:\vstsagent\A3\_work\_temp\e063c6c1-e334-11e8-96ca-cb244534022f.txt
2018-11-08T09:01:27.9515408Z ##[error]Unhandled: Unexpected end of JSON input
2018-11-08T09:01:27.9524437Z ##[error]Unhandled: Command failed: cscript.exe //Nologo C:\vstsagent\A3\_work\_tasks\VSTest_ef087383-ee5e-42c7-9a53-ab56c98420f9\2.142.12\node_modules\regedit\vbs\regListStream.wsf A

2018-11-08T09:01:28.0079953Z ##[error]Unhandled: Unexpected end of JSON input
2018-11-08T09:01:28.0095401Z ##[error]Unhandled: Command failed: cscript.exe //Nologo C:\vstsagent\A3\_work\_tasks\VSTest_ef087383-ee5e-42c7-9a53-ab56c98420f9\2.142.12\node_modules\regedit\vbs\regListStream.wsf A

2018-11-08T09:01:28.1547295Z Microsoft (R) Test Execution Command Line Tool Version 15.8.0
2018-11-08T09:01:28.1550589Z Copyright (c) Microsoft Corporation.  All rights reserved.
2018-11-08T09:01:28.1550786Z 
2018-11-08T09:01:28.1581289Z vstest.console.exe

The release itself keeps showing as "partially succeeded", which badly influences the automatic notifications, as the tests themselves are succeeding without problems. So far I haven't been able to find a solution in this context.

Does anyone have an idea of how to fix this? I'll be happy to provide more info if needed.

Solution

  • We just managed to get rid of the errors by re-adding the build agent in the old way (heading to _settings/agentqueues "Agent Pools" and using "Download Agent").

    Previously, we configured the agent using Deployment Groups: though I still don't know why, this apparently had something to do with the issue.