substrate-prometheus-endpoint: directly require the feature "tokio/net"

prdoc/pr_9355.prdoc

@@ -0,0 +1,86 @@
+title: 'substrate-prometheus-endpoint: directly require the feature "tokio/net"'
+doc:
+- audience: Node Dev
+  description: |-
+    The crate `substrate-prometheus-endpoint` use tokio items given by the feature "net" but it doesn't explictly requires it in the `Cargo.toml`. It compiles on master because `hyper-util` enables the feature "tokio/net". But upgrading `hyper-util` break this indirect enabling.
+
+    This fix the issue by directly setting "net" feature as required, as it is used.
+    We should also backport this ideally. It is not a breaking change given the code doesn't compile without the feature and only compiles if indirectly enabled by another crate.
+
+    # Reproduce:
+
+    To reproduce do `cargo update -p hyper-util && cargo check -p substrate-prometheus-endpoint`:
+
+    You will get the error:
+    ```
+    error[E0433]: failed to resolve: could not find `TcpListener` in `net`
+      --> substrate/utils/prometheus/src/lib.rs:89:29
+       |
+    89 |     let listener = tokio::net::TcpListener::bind(&prometheus_addr).await.map_err(|e| {
+       |                                ^^^^^^^^^^^ could not find `TcpListener` in `net`
+       |
+    note: found an item that was configured out
+      --> /home/gui/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.45.0/src/net/mod.rs:43:28
+       |
+    43 |     pub use tcp::listener::TcpListener;
+       |                            ^^^^^^^^^^^
+    note: the item is gated behind the `net` feature
+      --> /home/gui/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.45.0/src/net/mod.rs:38:1
+       |
+    38 | / cfg_net! {
+    39 | |     mod lookup_host;
+    40 | |     pub use lookup_host::lookup_host;
+    ...  |
+    51 | |     }
+    52 | | }
+       | |_^
+       = note: this error originates in the macro `cfg_net` (in Nightly builds, run with -Z macro-backtrace for more info)
+    help: consider importing this struct
+       |
+    20 + use std::net::TcpListener;
+       |
+    help: if you import `TcpListener`, refer to it directly
+       |
+    89 -     let listener = tokio::net::TcpListener::bind(&prometheus_addr).await.map_err(|e| {
+    89 +     let listener = TcpListener::bind(&prometheus_addr).await.map_err(|e| {
+       |
+
+    error[E0412]: cannot find type `TcpListener` in module `tokio::net`
+      --> substrate/utils/prometheus/src/lib.rs:99:24
+       |
+    99 |     listener: tokio::net::TcpListener,
+       |                           ^^^^^^^^^^^ not found in `tokio::net`
+       |
+    note: found an item that was configured out
+      --> /home/gui/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.45.0/src/net/mod.rs:43:28
+       |
+    43 |     pub use tcp::listener::TcpListener;
+       |                            ^^^^^^^^^^^
+    note: the item is gated behind the `net` feature
+      --> /home/gui/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.45.0/src/net/mod.rs:38:1
+       |
+    38 | / cfg_net! {
+    39 | |     mod lookup_host;
+    40 | |     pub use lookup_host::lookup_host;
+    ...  |
+    51 | |     }
+    52 | | }
+       | |_^
+       = note: this error originates in the macro `cfg_net` (in Nightly builds, run with -Z macro-backtrace for more info)
+    help: consider importing this struct
+       |
+    20 + use std::net::TcpListener;
+       |
+    help: if you import `TcpListener`, refer to it directly
+       |
+    99 -     listener: tokio::net::TcpListener,
+    99 +     listener: TcpListener,
+       |
+
+    Some errors have detailed explanations: E0412, E0433.
+    For more information about an error, try `rustc --explain E0412`.
+    error: could not compile `substrate-prometheus-endpoint` (lib) due to 2 previous errors
+    ```
+crates:
+- name: substrate-prometheus-endpoint
+  bump: patch

substrate/utils/prometheus/Cargo.toml

@@ -22,7 +22,7 @@ hyper-util = { features = ["server-auto", "server-graceful", "tokio"], workspace
 log = { workspace = true, default-features = true }
 prometheus = { workspace = true }
 thiserror = { workspace = true }
-tokio = { features = ["parking_lot"], workspace = true, default-features = true }
+tokio = { features = ["net", "parking_lot"], workspace = true, default-features = true }
 
 [dev-dependencies]
 hyper-util = { features = ["client-legacy", "tokio"], workspace = true, default-features = true }