Hello,

I'm currently looking into adding support for Alpine Linux to appstream-genearator so we can ship appstream data in Alpine Linux 3.12 (and as such postmarketOS) since we've recently gotten support for installing packages via GNOME Software. I figured it'd be good to discuss some things before I go ahead and start implementing something.

• I see most other backends parse the repository index manually. I'd rather not parse it manually since we use a custom format for our APKINDEX and I have D bindings for our package manager, apk-tools, anyway. Would it be acceptable to make the apk backend optional and depend on that lib?

• We currently don't embed file lists into our repository index, nor do we embed it in the metadata for our packages. This will hopefully be fixed in the next version of our package manager, but right now the only ways to know what files are in a package are to either peek into the package archive or to query https://pkgs.alpinelinux.org .