Drop GVariant support

[zeenix]

As I expressed in #1125:

• the whole gvariant support is getting too much to handle for me, especially mixed with zbus etc.
• I've long abandoned the plans of using gvariant as a dbus2 protocol (which was its original intention).
• gvariant crate exists and not only it is used by ostree folks, it actually lives in the ostree space and seems to be the officially blessed implementation.

So I'm inclined to drop this support in the zvariant 6.0.

[zeenix]

• gvariant crate exists and not only it is used by ostree folks, it actually lives in the ostree space and seems to be the officially blessed implementation.

A bit more context about this: I originally added gvariant support in hopes that ostree folks will use it, since gvariant provides a nice API but seems they went for the gvariant crate, even though (IMO) it has a non-intuitive strange API that is not serde-compatible.

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Anyway, another option here would be to split the gvariant support into a separate crate. However, I would not have the time and energy to do that. So if someone wants to take that up, please go ahead and let me me here.

[bilelmoussaoui]

A bit more context about this: I originally added gvariant support in hopes that ostree folks will use it, since gvariant provides a nice API but seems they went for the gvariant crate, even though (IMO) it has a non-intuitive strange API that is not serde-compatible.

After testing the gvariant API, it seems really not an alternative to zvariant in it current form.

I will have to look and and see how much effort would take to keep the gvariant format support in-tree by helping keeping it working, if that is a possibility.

[zeenix]

I will have to look and and see how much effort would take to keep the gvariant format support in-tree by helping keeping it working, if that is a possibility.

I feel bad about making you do this. 😔 Tell you what, if ostree would switch to zvariant, I promise to keep the gvariant support and maintain it too.

Is that something you'd want to look into?

[bilelmoussaoui]

Sure

[zeenix]

Sure

Great. I suggest making sure they'll be willing to accept such a contribution before putting any effort into it.

[bilelmoussaoui]

actually now that i checked the ostree repository, it doesn't seem to use the gvariant crate anywhere. Or you were talking about flat-manager which manipulate an ostree repo gvariant format manually in https://github.com/flatpak/flat-manager/blob/master/src/ostree.rs?

[zeenix]

actually now that i checked the ostree repository, it doesn't seem to use the gvariant crate anywhere.

I was referring to the only dependent of gvariant on crates.io, called ostree-ext but seems it has been moved into the bootc project:

https://github.com/containers/bootc/tree/main/ostree-ext

It does still use the gvariant crate.