pro build warning

[marlonhanks]

Questions

• Is this a bug concerning building of ink! smart contracts?
  • If yes then you might instead want to file a bug report to ink!'s build tool: https://github.com/paritytech/cargo-contract
• Is this a bug that appears when interacting with smart contracts via the Polkadot JS browser UI?
  • If yes then you might instead want to file a bug report to the Polkadot JS Apps project instead: https://github.com/polkadot-js/apps

FAQ

• Are you using the nightly Rust channel to compile your smart contract?
• Are you using an up-to-date cargo-contract? Check via cargo contract --version.
  • If you are unsure please tell us your version noted there.
• Are you using an up-to-date ink! version in your smart contract?
  • You can check this by looking into the [dependencies] section of your Cargo.toml.
  • If you are unsure please tell us your version noted there.

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Expected behavior
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Additional context
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warning: variable does not need to be mutable
   --> crates/env/src/chain_extension.rs:383:18
    |
383 |                 |mut output| {
    |                  ----^^^^^^
    |                  |
    |                  help: remove this `mut`
    |
    = note: `#[warn(unused_mut)]` on by default

warning: 1 warning emitted