Example code does not work out of the box

[ydirson]

Code samples "dumping all the machine’s links does not work out of the box:

• tokio dependency has to activate features (not sure what the minimal is, feature full does work)
• several names imported from netlink-proto-route are indeed implemented in netlink-proto-core

Did this example ever compile ? If it did, I feel it hints toward incompatible changes in the API that should have caused version bumps.

[ydirson]

Another one is https://github.com/rust-netlink/netlink-proto/blob/main/examples/dump_links_async.rs.

• figured out similarly that the use section should rather be like:

  use netlink_packet_core::{
      NetlinkHeader, NetlinkMessage, NLM_F_DUMP, NLM_F_REQUEST,
  };
  use netlink_packet_route::{
      LinkMessage, RtnlMessage,
  };
  

• figured out a Cargo.toml as follows (not really minimal, could not deactivate tokio_socket feature from netlink-proto as that removes new_connection() which the example uses):

  [package]
  name = "netlink-rs-notokio"
  version = "0.1.0"
  edition = "2018"
  
  [dependencies]
  futures = "0.3"
  async-std = { version = "1.12.0", features = ["attributes"] }
  netlink-proto = { version = "0.11.1" } #, default_features = false }
  netlink-packet-core = "0.5.0"
  netlink-packet-route = "0.15.0"
  

Note I also attempted to activate the smol_socket feature as the [[example]] section shows, but as the #[cfg(feature = "tokio_socket")] implies it does not help to get new_connection, tokio support not de-activatable (and it does not help with the error below).

Alas, it fails at runtime as follows:

$ RUST_BACKTRACE=1 ./target/debug/netlink-rs-notokio
thread 'main' panicked at 'there is no reactor running, must be called from the context of a Tokio 1.x runtime', /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/netlink-sys-0.8.4/src/tokio.rs:45:17
stack backtrace:
   0: rust_begin_unwind
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/panicking.rs:575:5
   1: core::panicking::panic_fmt
             at /builddir/build/BUILD/rustc-1.67.1-src/library/core/src/panicking.rs:64:14
   2: core::panicking::panic_display
             at /builddir/build/BUILD/rustc-1.67.1-src/library/core/src/panicking.rs:135:5
   3: tokio::runtime::scheduler::Handle::current
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.25.0/src/runtime/scheduler/mod.rs:191:13
   4: tokio::io::async_fd::AsyncFd<T>::with_interest
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.25.0/src/io/async_fd.rs:204:51
   5: tokio::io::async_fd::AsyncFd<T>::new
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.25.0/src/io/async_fd.rs:188:9
   6: <netlink_sys::tokio::TokioSocket as netlink_sys::async_socket::AsyncSocket>::new
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/netlink-sys-0.8.4/src/tokio.rs:45:17
   7: netlink_proto::connection::Connection<T,S,C>::new
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/netlink-proto-0.11.1/src/connection.rs:69:22
   8: netlink_proto::new_connection_with_codec
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/netlink-proto-0.11.1/src/lib.rs:284:9
   9: netlink_proto::new_connection
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/netlink-proto-0.11.1/src/lib.rs:239:5
  10: netlink_rs_notokio::main::main::{{closure}}
             at ./src/main.rs:22:33
  11: netlink_rs_notokio::main::{{closure}}
             at ./src/main.rs:18:1
  12: <async_std::task::builder::SupportTaskLocals<F> as core::future::future::Future>::poll::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/builder.rs:199:17
  13: async_std::task::task_locals_wrapper::TaskLocalsWrapper::set_current::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/task_locals_wrapper.rs:60:13
  14: std::thread::local::LocalKey<T>::try_with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:446:16
  15: std::thread::local::LocalKey<T>::with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:422:9
  16: async_std::task::task_locals_wrapper::TaskLocalsWrapper::set_current
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/task_locals_wrapper.rs:55:9
  17: <async_std::task::builder::SupportTaskLocals<F> as core::future::future::Future>::poll
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/builder.rs:197:13
  18: <futures_lite::future::Or<F1,F2> as core::future::future::Future>::poll
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-lite-1.12.0/src/future.rs:526:33
  19: async_executor::Executor::run::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-executor-1.5.0/src/lib.rs:237:31
  20: async_executor::LocalExecutor::run::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-executor-1.5.0/src/lib.rs:436:33
  21: async_io::driver::block_on
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-io-1.12.0/src/driver.rs:146:33
  22: async_global_executor::reactor::block_on::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-global-executor-2.3.1/src/reactor.rs:3:18
  23: async_global_executor::reactor::block_on
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-global-executor-2.3.1/src/reactor.rs:12:5
  24: async_global_executor::executor::block_on::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-global-executor-2.3.1/src/executor.rs:26:36
  25: std::thread::local::LocalKey<T>::try_with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:446:16
  26: std::thread::local::LocalKey<T>::with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:422:9
  27: async_global_executor::executor::block_on
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-global-executor-2.3.1/src/executor.rs:26:5
  28: async_std::task::builder::Builder::blocking::{{closure}}::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/builder.rs:171:25
  29: async_std::task::task_locals_wrapper::TaskLocalsWrapper::set_current::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/task_locals_wrapper.rs:60:13
  30: std::thread::local::LocalKey<T>::try_with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:446:16
  31: std::thread::local::LocalKey<T>::with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:422:9
  32: async_std::task::task_locals_wrapper::TaskLocalsWrapper::set_current
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/task_locals_wrapper.rs:55:9
  33: async_std::task::builder::Builder::blocking::{{closure}}
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/builder.rs:168:17
  34: std::thread::local::LocalKey<T>::try_with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:446:16
  35: std::thread::local::LocalKey<T>::with
             at /builddir/build/BUILD/rustc-1.67.1-src/library/std/src/thread/local.rs:422:9
  36: async_std::task::builder::Builder::blocking
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/builder.rs:161:9
  37: async_std::task::block_on::block_on
             at /home/builder/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.12.0/src/task/block_on.rs:33:5
  38: netlink_rs_notokio::main
             at ./src/main.rs:18:1
  39: core::ops::function::FnOnce::call_once
             at /builddir/build/BUILD/rustc-1.67.1-src/library/core/src/ops/function.rs:507:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.