Panic while compiling Moonbeam runtime

[mfornos]

We are trying to use the light client to connect to the Moonbeam network.

But it panics while compiling the runtime.

panicked at 'called `Result::unwrap()` on an `Err` value: InvalidRuntime(InvalidHeapPages(TooLarge))', /__w/smoldot/smoldot/light-base/src/json_rpc_service/background.rs:1282:14
file:///home/marc/Development/ocelloids/node_modules/smoldot/dist/mjs/instance/raw-instance.js:36
                throw new Error();
                      ^
Error
    at Object.onPanic (file:///home/marc/Development/ocelloids/node_modules/smoldot/dist/mjs/instance/raw-instance.js:36:23)
    at panic (file:///home/marc/Development/ocelloids/node_modules/smoldot/dist/mjs/instance/bindings-smoldot-light.js:52:20)
    at wasm://wasm/00fc8eb6:wasm-function[2764]:0xa0317
    at wasm://wasm/00fc8eb6:wasm-function[12523]:0x282f48
    at wasm://wasm/00fc8eb6:wasm-function[12513]:0x2823d5
    at wasm://wasm/00fc8eb6:wasm-function[12518]:0x282a47
    at wasm://wasm/00fc8eb6:wasm-function[12590]:0x2888ed
    at wasm://wasm/00fc8eb6:wasm-function[12621]:0x28ddce
    at wasm://wasm/00fc8eb6:wasm-function[1994]:0x83a4b
    at wasm://wasm/00fc8eb6:wasm-function[1497]:0x5492c

Context:

[smoldot] Chain initialization complete for polkadot. Name: "Polkadot". Genesis hash: 0x91b1…90c3. State root hash: 0x29d0d972cd27cbc511e9589fcb7a4506d5eb6a9e8df205f00472e5ab354a4e17. Network identity: 12D3KooWLvwb4xoELUUpFuohYGdEnZtdYuikJXKWA5mUyTtYiCCB. Chain specification or database starting at: 0xcbd8…793f (#16637440)
[smoldot] Parachain initialization complete for moonbeam. Name: "Moonbeam". Genesis hash: 0xfe58…b76d. State root hash: 0x74e54bafcf1ecdce51867078fa16f2902751d11473628ac19e89a5be20df3262. Network identity: 12D3KooWPnCpjre36yqeW9m151stms11FwnnTrCmjPCgMAMzAe8h. Relay chain: polkadot (id: 2004)
[sync-service-polkadot] GrandPa warp sync finished to #17272223 (0xdbf2…3f3b)
[runtime-polkadot] Finalized block runtime ready. Spec version: 9430. Size of `:code`: 1.4 MiB.
[runtime-moonbeam] Failed to compile runtime. Size of `:code`: 1.6 MiB.
Error: Failed to parse `:heappages` storage value: TooLarge
This indicates an incompatibility between smoldot and the chain.

It there anything that we can do to make it work with Moonbeam?

Thank you very much!

[tomaka]

The value at the storage key :heappages (0x3a686561707061676573) for Moonbeam is 0xed5c416273747261 (queried through a JSON-RPC server).

[tomaka]

cc https://github.com/paritytech/polkadot-sdk/issues/71

[mfornos]

Well... seemingly it is really set to "7021802807942536429" pages. A "solution" could be to limit the max heap pages number to a reasonable one. Maybe 65536 as in the fix of the linked issue? I was checking other networks and didn't found other network specifying ':heappages' so 2048 is being used.

Btw, i'm not aware of the implications for smoldot and how the pages are actually allocated. Will take a look just out of curiosity :D

[tomaka]

A "solution" could be to limit the max heap pages number to a reasonable one. Maybe 65536 as in the fix of the linked issue?

Smoldot needs to match the behavior of Substrate.

As far as I understand, Moonbeam made some modifications to their fork of Substrate so that it ignores the number of heap pages. It's unclear to me why they don't fix the on-chain value instead. If that's the case, then Moonbeam is incompatible with smoldot.

[XY-Wang]

Seems that the ignore_onchain_heap_pages flag was merged into Substrate.

References: https://github.com/paritytech/polkadot-sdk/blob/771c3fbde7ba3849298d6fc7df390fc6b5a04d2f/substrate/client/executor/src/executor.rs#L145 https://github.com/paritytech/polkadot-sdk/blob/771c3fbde7ba3849298d6fc7df390fc6b5a04d2f/substrate/client/executor/src/executor.rs#L657 https://github.com/paritytech/polkadot-sdk/blob/771c3fbde7ba3849298d6fc7df390fc6b5a04d2f/substrate/client/executor/src/executor.rs#L663

[tomaka]

If you want to move this issue forward, please find someone from Moonbeam and ask them for an explanation about this.

[tomaka]

The panic has been fixed in https://github.com/smol-dot/smoldot/pull/1570