Thanks for getting in touch.
Our step is limited to the Service Fabric PowerShell cmdlets that our scripts call through to. The options you can set on the step are forwarded from Octopus to this Calamari script. The
UnregisterUnusedVersions property is forwarded to the
Publish-UpgradedServiceFabricApplication cmdlet (which is a Service Fabric SDK method) and at that point it’s out of our control.
If there are additional arguments that the SDK allows you to set that are not supported by Octopus, you can override this powershell script with your own logic, so you can customise it if necessary. But from a quick look at the SDK, we don’t see any additional parameters that gives you finer control of these unused versions.
Sorry for the bad news, but hopefully that provides some clarity about what’s happening end-to-end and maybe you can find a compromise.