Nlohmann_json and json wraps are the same, just different versions

[danielcjacobs]

Is there an easy way to consolidate these into a single wrap?

[eli-schwartz]

https://github.com/mesonbuild/json

Meson build definitions for json (deprecated: use nlohmann_json)

The same thing happened for sqlite and libjpeg, but I guess @xclaesse overlooked this one. It should be removed from the website table and from the repo, but still made accessible via the v2 API in case people actually used the .wrap file (this is broadly how we handled deprecation in the v1 API, if I remember correctly).

Maybe @xclaesse has ideas for implementing this.

[xclaesse]

We need to be a bit more careful than what I've been when removing sqlite during transition from v1 to v2 because it broken "meson subprojects update": https://gitlab.freedesktop.org/gstreamer/gst-build/-/merge_requests/252.

We probably should not remove a project from releases.json, but instead add something like "deprecated_for": "json" and make meson warn and pick the new wrap instead?

[eli-schwartz]

Sounds reasonable, and we can have it be excluded from the website table too.

[eli-schwartz]

Maybe a "deprecated" section with "json": "nlohmann_json"? For compactness purposes.

EDIT: oh, but backwards compat will still have subprojects update fail. Does that raise exceptions or just skip the removed one? It is not like a deprecated wrap has updates anyway...

[xclaesse]

At least with latest meson (not sure about older version) it should skip, but will return error code at the end, which breaks CI scripts.

[bgilbert]

Proposed deprecation mechanism in #2529 and warning implementation in mesonbuild/meson#15309.