SwarmBuilder can not use mplex and yamux together

[oblique]

Summary

With the new SwarmBuilder you can not use mplex and yamux together. The test cases wrongly have feature = "mplex" which is not defined in Cargo.toml, thus the test never gets enabled.

Expected behavior

The following code should compile:

        let _ = SwarmBuilder::with_new_identity()
            .with_tokio()
            .with_tcp(
                Default::default(),
                libp2p_tls::Config::new,
                (
                    libp2p_yamux::Config::default(),
                    libp2p_mplex::MplexConfig::default(),
                ),
            )
            .unwrap()
            .with_behaviour(|_| libp2p_swarm::dummy::Behaviour)
            .unwrap()
            .build();

Actual behavior

I'm getting this error:

error[E0277]: the trait bound `(libp2p_yamux::Config, MplexConfig): phase::IntoMultiplexerUpgrade<TlsStream<multistream_select::negotiated::Negotiated<libp2p_tcp::tokio::TcpStream>>>` is not satisfied
   --> libp2p/src/builder.rs:174:17
    |
171 |               .with_tcp(
    |                -------- required by a bound introduced by this call
...
174 | /                 (
175 | |                     libp2p_yamux::Config::default(),
176 | |                     libp2p_mplex::MplexConfig::default(),
177 | |                 ),
    | |_________________^ the trait `phase::IntoMultiplexerUpgrade<TlsStream<multistream_select::negotiated::Negotiated<libp2p_tcp::tokio::TcpStream>>>` is not implemented for `(libp2p_yamux::Config, MplexConfig)`
    |
    = help: the trait `phase::IntoMultiplexerUpgrade<C>` is implemented for `(U1, U2)`
note: required by a bound in `tcp::<impl builder::SwarmBuilder<Tokio, tcp::TcpPhase>>::with_tcp`
   --> libp2p/src/builder/phase/tcp.rs:72:29
    |
50  |             pub fn with_tcp<SecUpgrade, SecStream, SecError, MuxUpgrade, MuxStream, MuxError>(
    |                    -------- required by a bound in this associated function
...
72  |                 MuxUpgrade: IntoMultiplexerUpgrade<SecStream>,
    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `tcp::<impl SwarmBuilder<Tokio, TcpPhase>>::with_tcp`
...
99  | impl_tcp_builder!("tokio", super::provider::Tokio, tokio);
    | --------------------------------------------------------- in this macro invocation
    = note: this error originates in the macro `impl_tcp_builder` (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try `rustc --explain E0277`.

Relevant log output

No response

Possible Solution

I got confused a bit with generics in that place, so I chouldn't fix it.

Version

0.53.0

Would you like to work on fixing this bug ?

No

[oblique]

Ok I found how to fix the issue (#4831).