Result conflict and ppxlib

[Halbaroth]

We have to use ppxlib >= 0.30.0 and prevent conflict with result < 1.5.

[bclement-ocp]

We shouldn't have a dependency on result at all, we don't use it. I thought we solved this by adding a version restriction on fmt instead; do we have other dependencies that bring in result?

We also don't use ppxlib, so we shouldn't have it as a dependency either. What is broken?

[Halbaroth]

ppxlib is used by recent ppx_blob. We have to use recent ppx_blob as older versions are not compatible with Dune > 3. If we don't use a recent version of ppxlib, it doesn't recognize user-defined binding operators:
https://v2.ocaml.org/manual/bindingops.html
I guess the AST of OCaml is not correct into too old ppxlib libraries.

I will check for the result dependency.

EDIT: if you prefer, I can add ppx_lib < 0.30.0 as a conflict clause instead of a dependency. It makes more sense.

[bclement-ocp]

ppxlib is used by recent ppx_blob. We have to use recent ppx_blob as older versions are not compatible with Dune > 3. If we don't use a recent version of ppxlib, it doesn't recognize user-defined binding operators:

Ah, so ppx_blob is the one that probably doesn't have proper dependency constraints, OK. Adding a conflicts clause on old ppxlib (with a comment that it's for ppx_blob) makes more sense then, good idea!

[bclement-ocp]

I think result is logs through ocplib-simplex, OK for that then :'(

[bclement-ocp]

Let's merge this as is then, since #815 was merged already it will make things easier for us. We can clean up the ppxlib dependency into a conflicts once we are done with 2.5.0