Compilation failed: the trait Injectable<DependencyMap, _, _> is not implemented for ...

[jdxj]

When I added a handler to the Dispatcher, it couldn't be compiled, but I changed the code a little bit and it was able to compile again.

Command::Aria2Version => {
            // The code below fails to compile.
            //     the trait `Injectable<DependencyMap, _, _>` is not implemented ...
            // match aria2c.get_version().await {
            //     Ok(version) => {
            //         bot.send_message(msg.chat.id, format!("{}", version))
            //             .await?
            //     }
            //     Err(e) => {
            //         error!("get version err: {:?}", e);
            //         bot.send_message(msg.chat.id, "get version err").await?
            //     }
            // }
            // The code below compiles.
            let version = aria2c.get_version().await.unwrap();
            bot.send_message(msg.chat.id, format!("{}", version))
                .await?
}

The complete code is here.

[jdxj]

I solved it myself, but I'm not sure if I understand it correctly. I hope someone can answer it. My solution is:
replaced the std::error::Error returned by aria2c.get_version() with anyhow::Result, because I saw that the impl_into_di macro requires Func to be Send + Sync

        impl<Func, Input, Output, $($generic),*> Injectable<Input, Output, ($($generic,)*)> for Asyncify<Func>
        where
            Input: $(DependencySupplier<$generic> +)*,
            Input: Send + Sync,
            Func: Fn($($generic),*) -> Output + Send + Sync + 'static,
            Output: Send + 'static,
            $($generic: Clone + Send + Sync),*
        {
            #[allow(non_snake_case)]
            #[allow(unused_variables)]
            fn inject<'a>(&'a self, container: &'a Input) -> CompiledFn<'a, Output> {
                let Asyncify(this) = self;
                Arc::new(move || {
                    $(let $generic = std::borrow::Borrow::<$generic>::borrow(&container.get()).clone();)*
                    let out = this( $( $generic ),* );
                    Box::pin(ready(out))
                })
            }
        }

I guess the reason why it fails to compile is that Box<dyn std::error::Error> does not satisfy Send + Sync, but anyhow::Result does.

[WaffleLapkin]

You are correct. Dptree requires the future to be Send, so you should generally use dyn Error + Send or, as you did, anyhow/eyre.