Error while dividing two u128/Balance types

Question

    #[ink(storage)]
    pub struct Variables {
        a: u128,
        b: u128,
        multiplier: u128
    }

    impl Variables {

        #[ink(constructor)]
        pub fn new(a: u128, b: u128) -> Self {
            Variables {
                a: a,
                b: b,
                multiplier: 1_000_000_000_000
            }
        }

        #[ink(constructor)]
        pub fn default() -> Self {
            Variables {
                a: Default::default(),
                b: Default::default(),
                multiplier: 1_000_000_000_000
            }
        }

        #[ink(message)]
        pub fn initializer(&mut self, a: u128, b: u128) -> bool{
            self.a = a;
            self.b = b;
            true
        }

        #[ink(message)]
        pub fn div(&self) -> u128 {
            (self.a*self.multiplier/self.b) as u128
        }
    }
}

when I try to build above contract i'm getting this error - ERROR: Validation of the Wasm failed.

ERROR: An unexpected panic function import was found in the contract Wasm.
This typically goes back to a known bug in the Rust compiler:
https://github.com/rust-lang/rust/issues/78744

As a workaround try to insert overflow-checks = false into your Cargo.toml. This will disable safe math operations, but unfortunately we are currently not aware of a better workaround until the bug in the compiler is fixed.

ERROR: An unexpected import function was found in the contract Wasm: _ZN4core9panicking5panic17h8d2687444d110f05E.
Import funtions must either be prefixed with 'memory', or part of a module prefixed with 'seal'

Ignore with --skip-wasm-validation

Answer 1

You should add these lines to your Cargo.toml file (as suggested)

[profile.dev]
overflow-checks = false

Note that it is not needed in ink! if you build with --release flag