Borrowed value does not live long enough when using async/await - rust

Question

I am trying to make two async api call and eventually get error E0597.
Here is a code:
async fn make_request() -> Result<()> {
.........
.........
.........
let mut result = client.get(uri).await?;
let some_key = result.headers().get("some_key");
let next_url = match some_key {
Some(url) => {
let some_result = client.get(Uri::from_static(url.to_str().unwrap())).await?
}
None => println!("....")
};
Ok(())
}
When I run this code the error "borrowed value does not live long enough argument requires that result is borrowed for `'static"

Answer 1

I have created a compile-able example based on your snipped to reproduce the error in the playground, and if you are able to do something like this in your question (for future reference), it usually helps you get more specific answers.
The Request passed into the function has no lifetime guarantees, so this will fail with the error you mentioned:
use http::{Request, Uri};
async fn make_request(result: &Request<()>) -> std::io::Result<()> {
match result.headers().get("some_key") {
// `url` is a reference to the string in the "some_key" header
Some(url) => {
let some_result = Uri::from_static(url.to_str().unwrap());
}
None => println!("....")
};
Ok(())
}
You can add that lifetime requirement, but that probably isn't what you need, and will likely give you the same error message, just in a different place:
async fn make_request_static(result: &'static Request<()>) -> std::io::Result<()> {
match result.headers().get("some_key") {
// because the request is static, so can be `url`
Some(url) => {
let some_result = Uri::from_static(url.to_str().unwrap());
}
None => println!("....")
};
Ok(())
}
Uri implements the FromStr trait, though, so you would be best off using that. There is no longer a lifetime requirement, so it can work with any string you pass in, even one which is currently borrowed:
// need to import the trait to use its methods
use std::str::FromStr;
async fn make_request_3(result: &Request<()>) -> std::io::Result<()> {
match result.headers().get("some_key") {
// because the request is static, so can be `url`
Some(url) => {
let some_result = Uri::from_str(url.to_str().unwrap());
}
None => println!("....")
};
Ok(())
}