Questions tagged [rust]
Questions about the Rust programming language, the primary language used in the Substrate ecosystem.
264
questions
3
votes
1
answer
165
views
Emiting events does not work with cross contract calling
When using cross contract calling on another contract which also emits
events the events of the original contract do not work anymore.
I get the following error.
error[E0283]: type annotations needed
...
- 491
0
votes
2
answers
122
views
How to add and use a crate in an ink smart contract/ ink storage?
I want to use the bytes crate in an ink! smart contract of mine.
Also I want to declare a Byte value in the ink_storage struct.
However, I cannot figure out how to do this.
After hours of trying and ...
- 491
1
vote
1
answer
82
views
Unable to calculate logarithm of a number error method log10 ln
when I tried to get a logarithm of a number Im getting following erros in Substrate how to fix this ?
437 | let cc = f32::log10(4 as f32);
| ^^^^^ function or ...
- 343
2
votes
1
answer
86
views
Error building node template: file name too long
I'm trying to build the latest substrate node template (without any modifications so far) and I'm getting the following error:
error: failed to run custom build command for `node-template-runtime v4.0....
- 1,053
2
votes
1
answer
250
views
How to decode events help on substrate using polkadot.js?
I have a base smart contract in rust with package manager cargo. In that smart contract I have some events which I'm emitting while function calling. For listing that events I have a service in java ...
1
vote
1
answer
23
views
Why does substrate extrinsic return a unit tuple ? What is the significance of that?
Most of return types are result with a success of a unit tuple, Like In rustic perspective, what is the significance of this?
- 773
4
votes
2
answers
877
views
error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
I am using the latest substrate-node-template few weeks back it was building fine.
But the same project isn't building now, I did not do any changes. Error is occurring in runtime interface. I am ...
- 183
1
vote
1
answer
58
views
(FIXED) Substrate forkless upgrade tutorial: pallet_scheduler has breaking changes [closed]
(This question was originally asked here: https://stackoverflow.com/questions/72056703/substrate-forkless-upgrade-tutorial-pallet-scheduler-has-breaking-changes)
I am following the Substrate forkless ...
- 1,280
2
votes
1
answer
61
views
Scale codec: Is there a way to extract an enum's arm's codec index value?
Using scale, an enum can be written like this:
#[derive(Debug, Clone, PartialEq, Eq, Encode, Decode)]
pub enum Block {
#[codec(index = 101)]
V1(BlockV1),
}
The #[codec(index = 101)], the 101 ...
2
votes
1
answer
49
views
I want to understand this trait syntax
I want to understand this code.
pub trait Trait: balances::Trait {
type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
}
Could you please explain in ...
- 91
1
vote
3
answers
408
views
How can manually generate same address from mnemonic as subkey without it?
Can someone tell me how can I generate a secret/privateKey/miniSecretKey, publicKey without subkey the tool from a mnemonic?
I am working on a c# implementation of the wallet generation and I'd ...
- 21
1
vote
0
answers
88
views
Getting error in rust while compiling substrate node-template [closed]
I am trying to add the staking pallet with other dependencies in node-template and getting this error during compiling, I will be thankful if someone help me to resolve this issue...
- 364
0
votes
1
answer
199
views
Error expected struct `AccountId32`, found associated type when saving an AccountId who
I have a data structure as follows
// definition for account id is
// pub type AccountId = <<Signature as Verify>::Signer as IdentifyAccount>::AccountId;
use primitives::{AccountId, ...
- 343
1
vote
1
answer
101
views
Building my substrate pallet - Rust errors
I am a beginner at learning Rust/substrate/Polkadot.
I am trying to build my custom substrate pallet
My goal is,
Create a custom Substrate pallet that allows only the Root origin account to control ...
- 11
2
votes
1
answer
177
views
Rust ink! Utc::now() from chrono libary returns : function or associated item not found in `chrono::Utc'
as the title suggests.
I imported chrono 0.4 just like in the documentation Here
And when i ever i call Utc::now() to get current UTC time, i get error that the function now() doesn't not exists.
Here ...
3
votes
1
answer
146
views
Contract call returns error "Found input with 28 bits, expected 8". Polkadot.js and ink contracts
as the title suggest, Im trying to call PSP22 token contract and read balanceOf() function, but i get error that im passing a too big of a input (27 instead of 8)
Im trying to invoke balanceOf() PSP22 ...
3
votes
1
answer
115
views
Can't submit an extrinsic signed by generated key pair
I was trying to submit items (extrinsics) to my Substrate blockchain instance, but it keeps getting rejected. I use the key pair I generate using from_string function from sp_core::crypto::Pair, but ...
- 145
3
votes
1
answer
57
views
Which toolchain should I use to build Substrate
My current toolchains and targets look like this
installed toolchains
--------------------
stable-x86_64-unknown-linux-gnu (default)
nightly-2022-01-01-x86_64-unknown-linux-gnu
nightly-x86_64-unknown-...
- 474
2
votes
1
answer
95
views
Can we write bridge smart contract using ink?
I was reading about ink smart contracts and was curious is it possible to make bridge using ink, as there is already parity-common-bridges present. It would be very helpful if someone knows about this ...
- 329
1
vote
1
answer
335
views
Substrate Rust generate key pair using sp_core::crypto::Pair
I'm pretty new with Substrate and Rust, but I was trying to generate a key pair using the from_string function of sp_core::crypto::Pair . I haven't had any luck and kept getting either ...
- 145
4
votes
1
answer
214
views
How can I decode an extrinsic or event dynamically in rust?
How can I decode an extrinsic or event dynamically in rust? (I want to be able to decode across all parachains)
A lot of the heavy lifting seems to be frame-metadata and scale-info. There's a desub ...
- 3,759
6
votes
1
answer
254
views
With subxt how can I subscribe to watch extrinsics?
There's some great examples of how to use subxt to listen to all events.
Polkadot-js events screen seem to show events grouped by the extrinsic that created them. Can I do the same in rust?
(if not ...
- 3,759
1
vote
0
answers
49
views
Best tools & settings for `VSCode` for *offline* Substrate development
Substrate builds are resource intensive. Running some of rust's best-in-class tools like rust-analyzer at least with default settings leads to continuous full use of most resources and take ...
Nuke♦
- 1,822
1
vote
1
answer
112
views
Fetch storage data and convert it to primitive types with subxt
I want to get the bool value from the flipper contract. I use Rust and subxt. But I cannot convert it to a primitive type.
let value: bool = api
.metadata()
.pallet("...
- 121
1
vote
1
answer
52
views
How to resolve conflicted dependency versions when import frame_support
I'm trying to pull on-chain asset data from Basilisk via subxt. The name field of this asset_details struct is a BoundedVec and I need to be able to run the into_inner() method to get the vec from ...
- 51
0
votes
1
answer
135
views
How to convert T::Moment to u64
Here is my code:
#[derive(Clone, Encode, Decode, PartialEq, RuntimeDebug, TypeInfo)]
#[scale_info(skip_type_params(T))]
pub struct PayInstallmentOrder<Account, Balance, Time> {
pub ...
- 207
1
vote
1
answer
326
views
trait bound `H256: TypeInfo` is not satisfied; `TypeInfo` is not implemented for `H256, H160, H64, ethereum_types::U256`
Frontier(pallet-ethereum) project failed to compile after updating from polkadot-v0.9.17 to v0.9.18
Compiling polkadot-runtime v0.9.18 (https://github.com/paritytech/polkadot?branch=release-v0.9....
- 1,193
5
votes
1
answer
120
views
How to create an iterator for a child storage trie?
I have a Storage Map which I am using to to store structs and a Storage Value to use for indexing this:
#[pallet::storage]
#[pallet::getter(fn consequences)]
/// Storage map holding basic Consequence ...
- 321
4
votes
1
answer
127
views
How do `subxt` and `substrate-api-client` libraries differ?
I understand that there are two main Rust client libraries for Substrate:
subxt
substrate-api-client
I've checked out the examples for both libraries and it seems to me that they are mostly the same....
- 379
11
votes
3
answers
557
views
How to have a mapping in a custom structure inside an ink! contract?
I'm a newbie with rust and substrate. I'm currently trying to build a PSP34 compatible smart contract (NFT) for documents. In this contract, I'd like to have the following structure:
#[derive(Default, ...
- 489
7
votes
1
answer
180
views
How do I verify a signature signed using Polkadot.js app with rust code
I am trying to write a discord bot using rust/serenity to verify signature signed using polkadot.js app. I use schnorrkel crate, wrap the message in <Bytes>...</Bytes> and use the verify ...
- 325
1
vote
1
answer
89
views
Call a variable from [pallet::call] in another pallet [closed]
I have declared a variable in balances/lib.rs inside a [pallet::call] function.
I want to call that variable at runtime in the staking pallet after the era completes.
Or is there a way to call the ...
- 975
9
votes
3
answers
189
views
Error adding Custom RPCs for pallet
I've been trying to add some rpc calls available for my node, but an error related to the 'getrandom' module appears (even tho I'm not even using it).
I have a very simple pallet that creates and ...
- 1,104
2
votes
1
answer
712
views
How to output debug log in `build.rs`? [closed]
I want to output some debug info in the wasm_builder, What is the right way to do this? We cannot use normally runtime log::debug!(...) approach here, as the build.rs is compiled with the node build ...
- 663
8
votes
1
answer
132
views
How to setup and RPC call that accepts a u128 input?
I cannot seem to setup a RPC call that accepts a u128 param.
I can input the following
let u128Input = new BN("10")
let output = await api.rpc.template.testRpc(u128Input);
but get an error ...
- 83
7
votes
1
answer
141
views
How to perform arithmetic operation on Option<BalanceOf<T>>?
Hello all developers and community members, I am very new to Substrate and Rust.
I am creating a pallet for NFT marketplace.
for storing out the NFT details I've created a struct as mentioned below.
...
- 125
3
votes
1
answer
36
views
pallet-mmr-rpc missing impl
this is my service config.
this is my rpc config.
this is error message.
- 733
2
votes
1
answer
221
views
substrate: missing generics for struct `pallet_democracy::GenesisConfig`
When attempting to build the Democracy pallet (pallet_democracy) within a runtime based on the polkadot-v0.9.15-1 branch, built native using Rust stable 1.57 and WASM using Rust nightly 2021-11-29, ...
3
votes
1
answer
274
views
What is the difference between dependencies and dev-dependencies in Cargo.toml
My question is What is the difference between dependencies and dev-dependencies in Cargo.toml. And for developing pallet, now I have to declare crate in dependencies
- 393
3
votes
2
answers
89
views
Attempting to build multiple runtimes, stopped by `AccountNonceApi_account_nonce` is already defined
Polkadot is capable of allowing you to defining the native runtimes you want included within the final node binary (with flags like polkadot-native, kusama-native and so on..). Attempting to port the ...
14
votes
2
answers
1k
views
Why do we need #![cfg_attr(not(feature = "std"), no_std)]
This attribute is applied to the item it is defined in and conditionally applies the no_std attribute if we are not using the "std" feature. Why do we need this and in which cases would the ...
4
votes
2
answers
158
views
std in conditional compilation [closed]
#![cfg_attr(not(feature = "std"), no_std)]
Does the "std" above reflect the rust standard library or the std feature defined in the cargo.toml for a given crate?
Also, for many of ...
10
votes
3
answers
365
views
Why is it a bad idea to use String in an ink! smart contract?
I've heard that it is a bad idea to use Rust's String type in an ink! smart contract.
Why is this so? And what is your recommendation to use instead for typical use cases of String ‒ so parsing input ...
- 313
9
votes
2
answers
273
views
Trait bounds not satisfied for `Balance` type
I was following this guide Configuring Genesis for Balances.
In my parachain, I replaced T::Balance with BalanceOf<T>
type BalanceOf<T> =
<<T as Config>::Currency as ...
- 1,193
7
votes
1
answer
102
views
How to programmatically get current unbonding information on the Polkadot relay chain?
Using either a Rust or JavaScript client library I would like to get the amount of DOT that is currently being unbonded on the relay chain.
Some staking information is available in the Polkadot JS ...
- 379
2
votes
2
answers
120
views
error: duplicate lang item in crate `std` (which `arrayvec` depends on): `panic_impl`
I am use the latest rust toolchain, compiler the pallet-ibc at the branch feature/dv-ics20 : https://github.com/octopus-network/substrate-ibc, this give the blow error.
suyinrong@suyinrongdeMacBook-...
- 21
4
votes
1
answer
203
views
T::Balance ... associated type `Balance` not found for `T`
I was following this guide:
Configuring Genesis for Balances
https://docs.substrate.io/how-to-guides/v3/basics/genesis/
but got this error:
associated type Balance not found for T, associated type ...
- 1,193
3
votes
2
answers
41
views
How can I have some of the functions in separate file?
I want to keep some helper functions in a separate file. How can I do that?
impl<T: Config> Pallet<T> {
fn get_citizen_accountid(citizenid: u128) ->
fn get_citizen_id(...
- 663
4
votes
1
answer
287
views
How to return the whole Mapping from a contract method?
I'm a newbie in Rust, Substrate, and blockchain development. I'm developing an ink! smart contract that store a list of items. Since the storage version of Vec is not available yet, I use a Mapping to ...
1
vote
3
answers
122
views
Substrate compatible crate for handling RSA encryption
Im working on a project where i want to store encrypted data on-chain and later reveal that data. For this process im thinking of using a trusted off-chain worker to act as a "key-manager". ...
