Azure devops to chef integration

Working on integrating Chef habitat with Azure Devops ( previously VSTS ). The build step successful, however in Release pipeline, in Package Export Task, exporting to in both the formats of Tar or Docker is failing due to addition on NULL parameter at the end of command execution.

Below are the logs

2019-10-04T02:30:35.1230139Z Use Sudo: true

2019-10-04T02:30:35.1280812Z Package files path: /home/ubuntu/myagent/_work/r1/a/toymisfit-CI/drop/vadirajbk_1-misfit_toys-0.1.0-20191003054406-x86_64-linux.hart

2019-10-04T10:40:20.0346815Z [command]/tmp/hab pkg export docker --url /home/ubuntu/myagent/_work/r2/a/react-CI/drop/vadirajbk_1-hello-0.1.0-20191004101054-x86_64-linux.hart null