Fail if a build results in an empty package

[luhring]

Melange should detect and fail for the case where a built APK file was left with nothing but directories and an SBOM.

See motivation and context here: wolfi-dev/os#5336 (comment)

[kaniini]

We need a way to allow this for some packages, like build-base and wolfi-base, which contain no actual data, but group dependencies together.

[Elizafox]

We need a way to allow this for some packages, like build-base and wolfi-base, which contain no actual data, but group dependencies together.

Perhaps set something in the melange config stating the package is a metapackage? Something like:

package:
  name: foobar
  empty: true

Alternatively, this could be a linter, which could be turned off. But I think I'd need a post-walking linter.

[luhring]

Perhaps set something in the melange config stating the package is a metapackage

I like the explicitness 👍

[Elizafox]

Perhaps set something in the melange config stating the package is a metapackage

I like the explicitness 👍

I found out there's already:

package:
  options:
    no-provides: true

So I wrote the linter in #700 to respect it.

Incidentally, #700 will close this I believe.

[Elizafox]

Completed in #700. This lint can be disabled if needed.