Request of updating the rust toolchain version

[Kailai-Wang]

Problem:

the current toolchain (nightly-2022-03-10) seems a bit old to compile polkadot-v0.9.28 cumulus dependencies. It complains about "unstable library feature" when compiling the worker with my-node-runtime pointing to litentry-parachain-runtime, which is sitting at polkadot-v0.9.28:

error[E0658]: use of unstable library feature 'vec_retain_mut'
   --> /home/kai/.cargo/git/checkouts/substrate-7e08433d4c370a21/34a0621/client/transaction-pool/src/graph/validated_pool.rs:207:12
    |
207 |                     sinks.retain_mut(|sink| match sink.try_send(*hash) {
    |                           ^^^^^^^^^^
    |
    = note: see issue #90829 <https://github.com/rust-lang/rust/issues/90829> for more information
    = help: add `#![feature(vec_retain_mut)]` to the crate attributes to enable

   Compiling pallet-transaction-payment-rpc v4.0.0-dev (https://github.com/paritytech/substrate?branch=polkadot-v0.9.28#34a06217)
For more information about this error, try `rustc --explain E0658`.
error: could not compile `sc-transaction-pool` due to previous error

I double-checked the crate sc-transaction-pool: it comes from our parachain only (from cumulus-relay-chain-interface), not in integritee-node, so you probably won't have such a problem.

For now I can work around this by forking substrate and patching it in worker TOML, but still as polkadot evolves it could grow to some point where patching is too much and we'd need a newer toolchain.

However, this might not be so easy though: it would require newer toolchain support from sgx-* crates. As far as I tested, simply changing the TC to a newer version wouldn't work out of the box.

If you have better ideas, please let me know!

Edit: oops I accidentally took away the 1000th issue, sorry 😂

[Kailai-Wang]

Btw, I'm not saying 0.9.28 parachain-node + 0.9.26 worker will work, in fact, I still get some crate version conflict in between, but that's another story

[haerdib]

Yeyy. Issue number 1000 🥳

The rust version is currently blocked by apache/incubator-teaclave-sgx-sdk#386 (comment), but usually they keep to their promise. So we can expect an update there soon.

Regarding your issue: I believe we've seen that before. Is it not fixable by manually downgrading the retain_mut library to version 0.1.4? Ofc, that's no long term fix, but since we're currently blocked by (maybe) substrate ( #992 (comment)) and teaclave, I don't think there's an easy fix.

[clangenb]

I deleted the above comments; v0.9.28 is no_std compatible, it was another error.

[Kailai-Wang]

Thanks both 👍

Is it not fixable by manually downgrading the retain_mut library to version 0.1.4?

I don't think it will help, as it's not about the crate version (in fact, we don't have such crate in parachain or substrate), it's about the compiler features, and I just noticed you did similar stuff here, and I had to patch sc-transaction-pool and sc-consensus-babe in substrate myself.

Anyways 0.9.28 parachain-node + 0.9.26 worker doesn't seem to compile together due to conflict crate versions, something like:

note: perhaps two different versions of crate `sc_consensus_epochs` are being used?

so I think the best bet for us is to go back to v0.9.26 temporarily

Never mind I saw the 0.9.28 PR is round the corner, we'll go v0.9.28

[haerdib]

They have not yet updated... I did a follow-up comment. apache/incubator-teaclave-sgx-sdk#386 (comment)

Let's hope for the best.

[clangenb]

Finally teaclave has published an update, see #1074.