Issue running inspec provisioner in packer on Azure

Running an azure pipeline with packer task. Attempting to run an inspec provisioner. It appears to start but fails immediately with very little error info.

    "type": "inspec",
    "profile": "<relative_path>/inspec_role_dir"

In log:
==> azure-arm: Provisioning with Inspec…

==> azure-arm: Executing Inspec: inspec exec <relative_path>/inspec_role_dir --backend ssh --host --user xxx\VssAdministrator --key-files C:\Users\VSSADM1\AppData\Local\Temp\packer-provisioner-inspec.yyyykey --port 50106 --input-file C:\Users\VSSADM1\AppData\Local\Temp\packer-provisioner-inspec.zzzz.yml -l debug

packer version is 1.7.6.