# Println! macro doesn't work printing values **URL:** \ **Category:** Rust SDK\ **Tags:** feedback, faqs\ **Created:** [June 21, 2024, 7:06am UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965 "2024-06-21T07:06:01Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![eesheng](https://avatars.discourse-cdn.com/v4/letter/e/2bfe46/32.png) [@eesheng](https://forum.fuel.network/u/eesheng)\ **Post date:** [June 21, 2024, 7:06am UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965/1 "2024-06-21T07:06:01Z")
I am facing this error, where unwrapping a call cannot returns this error. I just want to print the returned value… ```auto `FuelCallResponse` cannot be formatted with the default formatted ``` My ./test/harness.rs ```auto use fuels::{prelude::*, types::ContractId}; abigen!(Contract(name="MyContract", abi="out/debug/test_asset-abi.json")); #[tokio::test] async fn test_harness() { // Test code here let (instance, _id) = get_contract_instance().await; let result = instance.methods().deposit().call().await.unwrap(); let result2 = instance.methods().test_deposit_asset_id_same_generated().call().await.unwrap(); let _str_from_address: &str = result.to_string().as_str(); let r2_str_from_address: &str = result2.to_string().as_str(); println!("{:?}",_str_from_address); println!("{:?}",r2_str_from_address); } async fn get_contract_instance() -> (MyContract, ContractId) { // Launch a local network and deploy the contract let wallets = launch_custom_provider_and_get_wallets( WalletsConfig::new( Some(3), /* Three wallets */ Some(1), /* Single coin (UTXO) */ Some(1_000_000_000), /* Amount per coin */ ), None, None, ) .await .unwrap(); let wallet = wallets.get(0).unwrap().clone(); let id = Contract::load_from( "./out/debug/test_asset.bin", LoadConfiguration::default(), ) .unwrap() .deploy(&wallet, TxPolicies::default()) .await .unwrap(); let instance = MyContract::new(id.clone(), wallet); (instance, id.into()) } ``` My sway contract: ```auto // Constant Product AMM - Uniswap V2. contract; use std::{ constants::ZERO_B256, hash::sha256, asset::transfer, hash::Hash, asset_id::AssetId, asset::{ burn, mint_to, }, contract_id::ContractId, call_frames::{ msg_asset_id, }, context::msg_amount, string::String, }; abi MyContract { #[storage(read, write)] fn deposit()-> Address; #[storage(read)] fn test_deposit_asset_id_same_generated() -> Address; } impl MyContract for Contract { #[storage(read, write)] fn deposit() -> Address { let owner = msg_sender().unwrap(); let asset_id = msg_asset_id().bits(); let address_from_b256: Address = Address::from(asset_id); address_from_b256 } #[storage(read)] fn test_deposit_asset_id_same_generated() -> Address { let token_id = b256::zero(); let token_address = ZERO_B256; let sub_id = sha256((token_address, token_id)); let asset_id: b256 = AssetId::new(ContractId::this(), sub_id).bits(); let address_from_b256: Address = Address::from(asset_id); address_from_b256 } } ``` ---
**Author:** ![eesheng](https://avatars.discourse-cdn.com/v4/letter/e/2bfe46/32.png) [@eesheng](https://forum.fuel.network/u/eesheng)\ **Post date:** [June 21, 2024, 7:07am UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965/2 "2024-06-21T07:07:56Z")
println! macro doesn’t work at all, why it doesn’t work? ```auto use fuels::{prelude::*, types::ContractId}; abigen!(Contract(name="MyContract", abi="out/debug/test_asset-abi.json")); #[tokio::test] async fn test_harness() { // Test code here let (instance, _id) = get_contract_instance().await; let result = instance. Methods().deposit().call().await. Unwrap().value; let result2 = instance. Methods().test_deposit_asset_id_same_generated().call().await. Unwrap().value; println!("{:?}",result ); println!("{:?}",result2 ); } ``` ---
**Author:** ![naz3eh](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.fuel.network/naz3eh/32/2025_2.png) [@naz3eh](https://forum.fuel.network/u/naz3eh)\ **Post date:** [June 21, 2024, 10:37am UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965/3 "2024-06-21T10:37:42Z")
it seems like a rust error to me. could you share your rust version? and also the output for the `fuelup show` from your terminal ---
**Author:** ![eesheng](https://avatars.discourse-cdn.com/v4/letter/e/2bfe46/32.png) [@eesheng](https://forum.fuel.network/u/eesheng)\ **Post date:** [June 21, 2024, 12:52pm UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965/4 "2024-06-21T12:52:55Z")
This is my terminal running `cargo test` ```auto Compiling test_asset v0.1.0 (/home/lokicheck/Desktop/test_asset) warning: unused variable: `result2` --> tests/harness.rs:12:9 | 12 | let result2 = instance.methods().test_deposit_asset_id_same_generated().call().await.unwrap().value; | ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_result2` | = note: `#[warn(unused_variables)]` on by default warning: `test_asset` (test "integration_tests") generated 1 warning Finished `test` profile [unoptimized + debuginfo] target(s) in 1m 04s Running tests/harness.rs (target/debug/deps/integration_tests-c9599d2b0d721b79) running 1 test test test_harness ... ok test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.53s ``` This is my terminal running `fuelup show` ```auto Default host: x86_64-unknown-linux-gnu fuelup home: /home/lokicheck/.fuelup installed toolchains -------------------- latest-x86_64-unknown-linux-gnu (default) nightly-2024-05-28-x86_64-unknown-linux-gnu testnet-x86_64-unknown-linux-gnu active toolchain ---------------- latest-x86_64-unknown-linux-gnu (default) forc : 0.60.0 - forc-client - forc-deploy : 0.60.0 - forc-run : 0.60.0 - forc-crypto : 0.60.0 - forc-debug : 0.60.0 - forc-doc : 0.60.0 - forc-explore : 0.28.1 - forc-fmt : 0.60.0 - forc-lsp : 0.60.0 - forc-tx : 0.60.0 - forc-wallet : 0.7.1 fuel-core : 0.26.0 fuel-core-keygen : 0.26.0 fuels versions -------------- forc : 0.62.0 forc-wallet : 0.62.0 ``` ---
**Author:** ![naz3eh](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.fuel.network/naz3eh/32/2025_2.png) [@naz3eh](https://forum.fuel.network/u/naz3eh)\ **Post date:** [June 27, 2024, 11:04am UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965/5 "2024-06-27T11:04:49Z")
> [@eesheng](#): > > This is my terminal running `cargo test` > > ```auto > Compiling test_asset v0.1.0 (/home/lokicheck/Desktop/test_asset) > warning: unused variable: `result2` > --> tests/harness.rs:12:9 > | > 12 | let result2 = instance.methods().test_deposit_asset_id_same_generated().call().await.unwrap().value; > | ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_result2` > | > = note: `#[warn(unused_variables)]` on by default > > warning: `test_asset` (test "integration_tests") generated 1 warning > Finished `test` profile [unoptimized + debuginfo] target(s) in 1m 04s > Running tests/harness.rs (target/debug/deps/integration_tests-c9599d2b0d721b79) > > running 1 test > test test_harness ... ok > > test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.53s > > ``` Looking at the output for the `cargo test` it seems that the test is passing and it is just giving the warning. And for the `Println`, †he error you are encountering, can you try updating your `result` and `result2` to this ```auto let result = instance.methods().deposit().call().await.unwrap().value; let result2 = instance.methods().test_deposit_asset_id_same_generated().call().await.unwrap().value; ``` ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/fuel/original/2X/5/57d5a345cc15a64b636e0d56e042857f8a0e80b1.png) [@system](https://forum.fuel.network/u/system)\ **Post date:** [July 18, 2024, 7:05am UTC](https://forum.fuel.network/t/println-macro-doesnt-work-printing-values/5965/6 "2024-07-18T07:05:10Z")
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