Cannot create signed extrinsic on acala network

[DanielMS93]

I am trying to sign a swap_with_exact_supply transaction on the acala network. I am using code that used to work with no problem on substrate-interface v1.0.5 but now seems to be struggling.

The issue seems to arise during the processing of the generated payload where it expects the nonce to be a Dict whilst of course it is an int.

This is my call

{'call_module': 'Dex', 'call_function': 'swap_with_exact_supply', 'call_params': [{'name': 'path', 'value': [{'Token': 'AUSD'}, {'Token': 'ACA'}]}, {'name': 'supply_amount', 'value': 685233204169165}, {'name': 'min_target_amount', 'value': 2132526743724632}]}

And i get type int is not iterable.

Is this an issue you are aware of? any ideas as to what might be causing it?

[DanielMS93]

further info from some investigations:

---

[DanielMS93]

I think the signed extensions are wrong...

[DanielMS93]

ok i think the type for the nonce enum is incorrect? it is currently set to be scale_info::601 whilst i think it should be the same as tip? i.e. scale_info::604?

[arjanz]

Confirmed, I debugged as well and there are currently actually several issues:

• [ ] Unsupported signed_extension SetEvmOrigin. Shouldn't be a problem though, because it doesn't seems to add any addition payload to the extrinsic or signature.
• [ ] The CheckNonce extension seems indeed changed to a Struct type, requiring the input to be {'nonce': 5} in stead of the int 5. This is causing the mentioned exception to be thrown. I will have to change the input to match the type of the CheckNonce extension. A workaround could be to for the time being wrap the nonce e.g.: substrate.create_signed_extrinsic(call=call, keypair=keypair, nonce={'nonce': nonce})
• [ ] But this is not the only issue, the in Substrate introduced RuntimeApi call to retrieve the nonce required manual type definition override (at least until MetadataV15 is available in Substrate). There is also a way to workaround this, I will look into this
• [ ] There is unfortunately also an issue with the recently changed ExtrinsicSignature detection, which cannot be easily worked around with, I will have to fix this and release before it's usable for Acala.

[arjanz]

ok i think the type for the nonce enum is incorrect? it is currently set to be scale_info::601 whilst i think it should be the same as tip? i.e. scale_info::604?

The type is correct, because this is retrieved from the embedded metadata (substrate.metadata[1][1]['extrinsic']['signed_extensions'].value), but the issue is that the py-substrate-interface library assumes its an Compact when it passes an int in the encode() method. This needs to be changed to modify the input (or maybe better, to make py-scalecodec tolerate a non-dict input for a Struct when it only has 1 element. (e.g. 6 turns automatically into {'nonce': 6}

[arjanz]

I'm running out of time today, but I will address this asap, as it blocks usage for networks like Acala.

[arjanz]

What you could try as a temporary workaround is:

keypair = Keypair.create_from_uri("//Alice")
nonce = substrate.get_account_nonce(keypair.ss58_address)
extrinsic = substrate.create_signed_extrinsic(call=call, keypair=keypair, nonce={'nonce': nonce})

This seems to work

[DanielMS93]

thanks so much for getting back. oh interesting! i will give it a try and let you know

[arjanz]

This seems to work

Too soon.. I forgot I already locally changed https://github.com/polkascan/py-substrate-interface/blob/b96c6124cf3a2ba52413fc4218e78ad5ec9e77d6/substrateinterface/base.py#L1959

to if type(signature_cls.type_mapping) is list:

which is a dirty workaround, but if it's urgent you can get it working now by changing that.

[DanielMS93]

ok nice, i have an extrinsic!! do let me know when this is more properly fixed :) but all good for now

[DanielMS93]

no pressure at all of course but helpful for planning, when do u think you'll be able to make a release with these fixes?

[arjanz]

Most likely there will be a release later today, I'm working on a fix right now

[arjanz]

Fix released: https://github.com/polkascan/py-substrate-interface/releases/tag/v1.5.2