Difficulties in the record_wav.rs example

[JContro]

Hi, if I try and run the record_wav.rs code, I get the following errors. I am relatively new to rust, which is why i am finding it difficult.

Here is the error:

error: cannot find derive macro Parserin this scope --> src/main.rs:9:10 | 9 | #[derive(Parser, Debug)] | ^^^^^^ | note:Parser` is imported here, but it is only a trait, without a derive macro
--> src/main.rs:2:5
|
2 | use clap::Parser;
| ^^^^^^^^^^^^

error: cannot find attribute command in this scope
--> src/main.rs:10:3
|
10 | #[command(version, about = "CPAL record_wav example", long_about = None)]
| ^^^^^^^

error: cannot find attribute arg in this scope
--> src/main.rs:13:7
|
13 | #[arg(short, long, default_value_t = String::from("default"))]
| ^^^

error[E0433]: failed to resolve: use of undeclared crate or module anyhow
--> src/main.rs:31:25
|
31 | fn main() -> Result<(), anyhow::Error> {
| ^^^^^^ use of undeclared crate or module anyhow

error[E0433]: failed to resolve: use of undeclared crate or module anyhow
--> src/main.rs:126:32
|
126 | return Err(anyhow::Error::msg(format!(
| ^^^^^ not found in anyhow
|
help: consider importing one of these items
|
2 | use clap::Error;
|
2 | use clap::error::Error;
|
2 | use core::error::Error;
|
2 | use core::fmt::Error;
|
and 4 other candidates
help: if you import Error, refer to it directly
|
126 - return Err(anyhow::Error::msg(format!(
126 + return Err(Error::msg(format!(
|

error[E0599]: no function or associated item named parse found for struct Opt in the current scope
--> src/main.rs:32:20
|
11 | struct Opt {
| ---------- function or associated item parse not found for this struct
...
32 | let opt = Opt::parse();
| ^^^^^ function or associated item not found in Opt
|
= help: items from traits can only be used if the trait is implemented and in scope
= note: the following traits define an item parse, perhaps you need to implement one of them:
candidate #1: Parser
candidate #2: TypedValueParser

warning: unused import: StreamTrait
--> src/main.rs:3:44
|
3 | use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
| ^^^^^^^^^^^
|
= note: #[warn(unused_imports)] on by default

Some errors have detailed explanations: E0433, E0599.
For more information about an error, try rustc --explain E0433.`

And this is my cargo.toml

[dependencies]
clap = "4.1.6"
cpal = "0.15.0"
ringbuf = "0.3.2"
hound = "3.5.0"

All in all, I am just looking to record some audio from the default audio interface.

Any help would be hugely appreciated

[geieredgar]

This might be a little late, but you need to enable the derive feature of clap to be able to use #[derive(Parser)]. So in your dependencies, replace

clap = "4.1.6"

with

clap = { version = "4.1.6, features = ["derive"] }

It is common practice in the Rust ecosystem to put the derive macros behind a derive feature-gate, because they come with a compile-time cost you don't want to pay if you aren't using them.

The other errors are related to the missing derive macro, except for the anyhow one, which you need to add to your dependencies.

[est31]

@geieredgar thanks for helping out @JContro . I will close this as the question is answered and this is not a cpal bug.