see Releases for binary builds
to build from source, use the make Makefile
appmanifest takes a pkg and prints an application manifest
the current version only creates the assets array.
The documentation says the metadata is required, but installs work without the metadata dict.
Adding one only affects what shows up in Launchpad
appmanifest [options] /path/to/some.pkg
-url string
url of the pkg as it will be on the server
-version
prints the version