Evgenii Lepikhin schreef op vr 01-04-2022 om 01:30 [+0300]:
> nom-7.0 is not forward compatible with nom-7.1. I need 7.1 for future
> contributions and this is why I added it into patchset.

Related: to reduce duplication, you can do

(define-public rust-nom-7.1
  (package
    (inherit rust-nom-7)
    [...]))

that way, you can ‘copy’ the synopsis of rust-nom-7 without writing it
down again.

Also, if semver is used here, nom-7.0 is compatible with nom-7.1 (not
sure about the terminology here -- forwards? backwards?, but updating
it shouldn't cause any problems if semver is followed correctlu).

> In developer's manifest of nom-7.1 dependency on rust-minimal-lexical
> has been updated from 0.1 to 0.2. For both versions dependencies on
> exact versions on rust-minimal-lexical are pinned by crate developers
> and we cannot change it at will

We can do that, with some 'substitute*'.  It is not guaranteed that it
will actually build, but there's a good chance that it will.  Or that
it fails.  Hard to say in advance.  See, e.g., rust-version-sync@0.8.

Greetings,
Maxime.