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Version: 6.x

no_main

What it does​

Checks if a contract is annotated with the no_main inner attribute.

Why is this necessary?​

Contracts must be annotated with no_main inner attribute when compiled for on-chain execution.

Example​

// Bad: Contract does not contain the `no_main` attribute,
// so it cannot be compiled to Wasm
#![cfg_attr(not(feature = "std"), no_std)]
#[ink::contract]
mod my_contract { /* ... */ }

Use instead:

#![cfg_attr(not(feature = "std"), no_std, no_main)]
#[ink::contract]
mod my_contract { /* ... */ }