How to create a metapackage

[Ole Streicher <olebole@debian.org>]

Hi,

I want to create two metapackages "python-astropy-all" and
"python3-astropy-all" which install astropy and all affiliated
packages. However, I could not find a good tutorial for this:

* Should it be native or not?

It looks like usually metapackages are native; however in my case the
package would be created in cooperation with upstream [1], and possible
created/maintained on the base of some data downloaded from upstream
(the list of available packages; however, probably not with a specific
release data).

* How to declare dependencies?

I guess that they should be either "Recommends", or "Suggests", but not
"Depends", right? (So that one can deinstall a single package without
deleting all others)

* What is the usual source layout?

Is this just a "debian/ subdir, containing "compat", "control",
"changelog" "source/format", "copyright"? What about "rules"? Should it
be empty in the simplest case?

* Should a metapackage be coordinated somehow? Or do I just write an ITP
  and later upload it?

* Anything else to take care of?

Best regards

Ole

[1] https://github.com/astropy/astropy/pull/3762