In the Octopus Dashboard I navigated to Library/Packages, selected a package, and clicked Download on my Mac (Catalina 10.15.6 (19G2021)). I then renamed the .nupkg to .zip and attempted to open but receive the error “Unable to expand . it is an unsupported format”.
I’m able to do the same .nupkg rename to .zip on Windows and it works.
For normal NuGet packages from sources like nuget.org I’m able to rename to zip and browse contents on the Mac.
The same package is able to be extracted okay on a Linux build agent but I expect to be able to download the package, rename to zip, and explore the contents for any package downloaded from the Portal regardless of the OS and browser.