[coq.dev] depends on zarith

[liyishuai]

Since rocq-prover/rocq#11742

Fixes rocq-prover/rocq#12937

[RalfJung]

@ejgallego which version of ZArith does Coq need? The docs say 1.8, the opam file says 1.9.1.

[erikmd]

Also, shouldn't the "num" dependency be removed as well?

[erikmd]

On second thought, rocq-prover/rocq#11742 says We thus keep the num library linked for now until micromega is ported., so forget my previous comment…

[erikmd]

@RalfJung

which version of ZArith does Coq need? The docs say 1.8, the opam file says 1.9.1.

it seems there is no version 1.8 available in opam-repository:

$ opam show zarith
<><> zarith: information on all versions ><><><><><><><><><><><><><><><><><><><>
name                   zarith
[…]
all-versions           1.1  1.2  1.3  1.4  1.4.1  1.5  1.6  1.7  1.7-1  1.9.1

[RalfJung]

it seems there is no version 1.8 available in opam-repository:

Interesting.
That would make >= 1.8 work though... but I guess let's keep this consistent with the file in the Coq repo.