Fuzz Testing & Nightly Cargo udeps are failing due to prost-derive

[MattDavis00]

As mentioned, Fuzz Testing & Nightly Cargo udeps are failing due to prost-derive.

   Compiling prost-derive v0.6.1
error[E0034]: multiple applicable items in scope
   --> /home/runner/.cargo/registry/src/github.com-1ecc6299db9ec823/prost-derive-0.6.1/src/lib.rs:111:14
    |
111 |             .intersperse(quote!(|));
    |              ^^^^^^^^^^^ multiple `intersperse` found
    |
    = note: candidate #1 is defined in an impl of the trait `Iterator` for the type `Map<I, F>`
    = note: candidate #2 is defined in an impl of the trait `Itertools` for the type `T`
help: disambiguate the associated function for candidate #1
    |
107 ~         let tags = Iterator::intersperse(field
108 +             .tags()
109 +             .into_iter()
110 +             .map(|tag| quote!(#tag)), {
111 +         let mut _s = $crate::__private::TokenStream::new();
112 +         $crate::quote_each_token!(_s $($tt)*);
  ...
help: disambiguate the associated function for candidate #2
    |
107 ~         let tags = Itertools::intersperse(field
108 +             .tags()
109 +             .into_iter()
110 +             .map(|tag| quote!(#tag)), {
111 +         let mut _s = $crate::__private::TokenStream::new();
112 +         $crate::quote_each_token!(_s $($tt)*);

[MattDavis00]

Parsec interface is running 0.6.1 and Parsec service is running 0.7.0.
An attempt at updating the Parsec interface to use prost 0.7.0 & prost-build 0.7.0 does not seem to fix the issue as seen here

[MattDavis00]

Seems to be related to rust-lang/rust#88878

[MattDavis00]

Seems to have been picked up within the prost crate here tokio-rs/prost#526
Looks like the fix is either pin the nightly builds to an older version or update prost to 0.8.0

[MattDavis00]

Updating prost to 0.8.0 seems to fix the itertools .intersperse() conflict. It however raises some additional errors:
https://github.com/MattDavis00/parsec/actions/runs/1233575094
https://github.com/MattDavis00/parsec/actions/runs/1233578406

[ionut-arm]

Those ones are fixed if you do a cargo update, I think, but the bigger problem is that we can't update prost for now because it conflicts with our Minimum Rust Supported Version, see #471

I've added this as a discussion point for today's meeting.

[hug-dev]

Hey @ggardet!
Small question. Reading from the rust.spec file of this page (you linked when I asked you in a previous issue), can we assume that Leap 15.3 is now using Rust version 1.53.0? If that's the case, can we update our CI scripts to use that as our Minimum Rust Supported Version?

[ggardet]

Hey @ggardet!
Small question. Reading from the rust.spec file of this page (you linked when I asked you in a previous issue), can we assume that Leap 15.3 is now using Rust version 1.53.0? If that's the case, can we update our CI scripts to use that as our Minimum Rust Supported Version?

Indeed, rust 1.53 is now available from the update channel. So, you should be able to bump the min version safely.