Help maintainers manage a roll-out with new constraints

[dsheets]

From http://lists.ocaml.org/pipermail/opam-devel/2015-June/001129.html:

When you do a release you may have to modifiy the constraints of other packages. How are you suppose to handle this with opam-publish ?

opam-publish could help here by checking dependent packages and prompting the user to check or constrain them. This kind of functionality might then result in a sequence of PRs which would need to be orchestrated by local monitoring or a third-party service.

This is definitely a feature wish.

[dsheets]

From @dbuenzli:

But then maybe could we get a nice UI to do that ?

e.g. opam publish constraints uuseg.0.8.0 —depends 'uucp,{>= "0.9.1" & < "1.0.0" }'

The better the tooling, the lazier I become.

[dbuenzli]

Was just thinking about this and maybe the command line is not very adapted for that (special characters). Maybe we should define a simple file format of the form

$PKG CONSTRAINT (add|remove) CONSTRAINT

This would also easily allow to (re)publish as it is possible right now with opam publish submit.

[Drup]

I was going to add a feature wish for this exact feature. So +1. :)