Package installation allows Sparkle to update your application by downloading and installing a package, pkg, or multi-package, mpkg without user interaction except for asking for an administrator password.
Note package installation should only be used for apps with very custom installation needs that cannot be satisfied by distributing a regular app bundle. For Sparkle, the downsides of using package updates are:
generate_appcast toolApplications that install daemons or install system extensions do not need to distribute package installers.
As of Sparkle 2.7.3, installing package updates may not work in development builds of apps where Sparkle’s helper tools are not usually re-signed. If this is the case, please test Sparkle either from a notarized version of your app, or from a version that was installed by your package installer.
Sparkle supports serving and signing flat *.pkg or *.mpkg packages directly without having to zip or archive them. This method requires users from old versions of your application to be using Sparkle 1.26 or later. If you have users running older versions of Sparkle, you can expedite migration by switching to a new appcast, or use Archived Package Installation until the majority of your users update.
This method is the recommended way of serving package based updates because it avoids redundant re-compression and metadata.
A package installation occurs when Sparkle finds a *.pkg or *.mpkg file in the root of the download archive (e.g, from within a .zip).
Note: For Sparkle 2, you must also add sparkle:installationType="package" to your appcast item’s enclosure for updating archived packages.