Panic upon establishing client connection

[ggwpez]

I am trying to connect to different nodes with the Subxt library and hit this panic when connecting to a specific node: RuntimeCall exists in V14; qed.
Can you please make this an error instead of a panic so my program does not crash?

Stack trace

thread 'main' panicked at 'RuntimeCall exists in V14; qed', /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-metadata-0.31.0/src/from_into/v14.rs:319:10
stack backtrace:
   0: rust_begin_unwind
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/std/src/panicking.rs:593:5
   1: core::panicking::panic_fmt
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/panicking.rs:67:14
   2: core::panicking::panic_display
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/panicking.rs:150:5
   3: core::panicking::panic_str
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/panicking.rs:134:5
   4: core::option::expect_failed
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/option.rs:1952:5
   5: core::option::Option<T>::expect
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/option.rs:898:21
   6: subxt_metadata::from_into::v14::generate_outer_enums
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-metadata-0.31.0/src/from_into/v14.rs:311:21
   7: subxt_metadata::from_into::v14::v14_to_v15
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-metadata-0.31.0/src/from_into/v14.rs:156:23
   8: subxt_metadata::from_into::v14::<impl core::convert::TryFrom<frame_metadata::v14::RuntimeMetadataV14> for subxt_metadata::Metadata>::try_from
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-metadata-0.31.0/src/from_into/v14.rs:15:9
   9: <T as core::convert::TryInto<U>>::try_into
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/convert/mod.rs:755:9
  10: <subxt_metadata::Metadata as parity_scale_codec::codec::Decode>::decode
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-metadata-0.31.0/src/lib.rs:640:57
  11: <subxt::metadata::metadata_type::Metadata as parity_scale_codec::codec::Decode>::decode
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-0.31.0/src/metadata/metadata_type.rs:71:9
  12: subxt::rpc::rpc::Rpc<T>::metadata::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-0.31.0/src/rpc/rpc.rs:401:34
  13: subxt::client::online_client::OnlineClient<T>::fetch_latest_stable_metadata::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-0.31.0/src/client/online_client.rs:158:24
  14: subxt::client::online_client::OnlineClient<T>::fetch_metadata::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-0.31.0/src/client/online_client.rs:144:57
  15: <futures_util::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/future/maybe_done.rs:95:38
  16: <futures_util::future::join::Join3<Fut1,Fut2,Fut3> as core::future::future::Future>::poll
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/future/join.rs:55:33
  17: subxt::client::online_client::OnlineClient<T>::from_rpc_client::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-0.31.0/src/client/online_client.rs:95:10
  18: subxt::client::online_client::OnlineClient<T>::from_url::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/subxt-0.31.0/src/client/online_client.rs:79:57
  19: subquery::endpoints::{{closure}}::{{closure}}::{{closure}}
             at ./src/main.rs:46:42
  20: <futures_util::stream::futures_unordered::FuturesUnordered<Fut> as futures_core::stream::Stream>::poll_next
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/stream/futures_unordered/mod.rs:518:17
  21: futures_util::stream::stream::StreamExt::poll_next_unpin
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/stream/stream/mod.rs:1632:9
  22: <futures_util::stream::stream::buffer_unordered::BufferUnordered<St> as futures_core::stream::Stream>::poll_next
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/stream/stream/buffer_unordered.rs:75:15
  23: <futures_util::stream::stream::collect::Collect<St,C> as core::future::future::Future>::poll
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-util-0.3.28/src/stream/stream/collect.rs:50:26
  24: subquery::endpoints::{{closure}}
             at ./src/main.rs:59:10
  25: subquery::main::{{closure}}
             at ./src/main.rs:12:26
  26: tokio::runtime::park::CachedParkThread::block_on::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/park.rs:282:63
  27: tokio::runtime::coop::with_budget
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/coop.rs:107:5
  28: tokio::runtime::coop::budget
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/coop.rs:73:5
  29: tokio::runtime::park::CachedParkThread::block_on
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/park.rs:282:31
  30: tokio::runtime::context::blocking::BlockingRegionGuard::block_on
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/context/blocking.rs:66:9
  31: tokio::runtime::scheduler::multi_thread::MultiThread::block_on::{{closure}}
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/scheduler/multi_thread/mod.rs:87:13
  32: tokio::runtime::context::runtime::enter_runtime
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/context/runtime.rs:65:16
  33: tokio::runtime::scheduler::multi_thread::MultiThread::block_on
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/scheduler/multi_thread/mod.rs:86:9
  34: tokio::runtime::runtime::Runtime::block_on
             at /Users/vados/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.32.0/src/runtime/runtime.rs:349:45
  35: subquery::main
             at ./src/main.rs:20:5
  36: core::ops::function::FnOnce::call_once
             at /rustc/d5c2e9c342b358556da91d61ed4133f6f50fc0c3/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Code for reproduction is here: subquery.zip (just cargo r).

[lexnv]

Hey Oliver,

Subxt is expecting the RuntimeCall and RuntimeEvent to be part of the metadata V14 for substrate-based chains.
This is part of converting the metadata V14 to the V15 format.

Indeed for some custom chains, this assumption might not hold true. I'm wondering are you targeting a live-chain or a local-node? 🤔

To avoid the panic, I believe we could extend generate_runtime_error_type()

[jsdw]

I'm curious to know when a RuntimeCall would ever not exist in a chain. But I agree that we should at least make it an error and not a panic (we should avoid panicking when user provided data (ie the metadata) isn't the format we expect).

The code to reproduce basically extracts endpoints from https://github.com/polkadot-js/apps/blob/master/packages/apps-config/src/endpoints/productionRelayPolkadot.ts and then tries to build a client from each of them, so I guess that one of those is missing a RuntimeCall, so let's also find out which one if we can, and look at its metadata!

[lexnv]

The following url was causing the panic "wss://c1.hashed.live:443".

Inspecting the metadata of that chain concluded that the RuntimeCall enum was not present in the portable registry. However, a Call enum was present which contained identical information:

            "id": 293,
            "type": {
              "path": [
                "hashed_parachain_runtime",
                "Call"
              ],
              "def": {
                "variant": {
                  "variants": [
                    {
                      "name": "System",
                      "fields": [
                        {
                          "type": 134,
                          "typeName": "self::sp_api_hidden_includes_construct_runtime::hidden_include::dispatch\n::CallableCallFor<System, Runtime>"
                        }
                      ],
                      "index": 0

As such have created a PR that:

• try to find RuntimeCall enum in portable registry
• try to find Call enum in portable registry
• if fallback fails, then generate a RuntimeCall enum

Idem for RuntimeEvent and RuntimeError. Tested the PR against Oliver's example and it works fine so far.

Thanks again Oliver for raising this!