fix default features leak

[name1e5s]

The same as #1986
Fix some default features leaks.

[mxinden]

I am a bit confused neither libp2p-mplex, libp2p-noise nor libp2p-request-response have any features. Can you explain what this change does?

[name1e5s]

I am a bit confused neither libp2p-mplex, libp2p-noise nor libp2p-request-response have any features. Can you explain what this change does?

Some features in libp2p-core can't turn off. For example, when we add the following code to Cargo.toml

libp2p = { version = "0.39", optional = true, default-features = false, features = [ "tcp-tokio", "noise", "mplex", "request-response" ] }

We can find that libp2p-core still have default features on, causing an unnecessary dependency libsecp256k1 being wrongly imported:

➜  sz git:(master) ✗ cargo tree -e features -i libp2p-core
libp2p-core v0.29.0
└── libp2p v0.39.1
    ├── libp2p feature "libp2p-mplex"
    │   └── libp2p feature "mplex"
    │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz)
    │           └── sz feature "default" (command-line)
    ├── libp2p feature "libp2p-noise"
    │   └── libp2p feature "noise"
    │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz) (*)
    ├── libp2p feature "libp2p-request-response"
    │   └── libp2p feature "request-response"
    │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz) (*)
    ├── libp2p feature "libp2p-tcp"
    │   └── libp2p feature "tcp-tokio"
    │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz) (*)
    ├── libp2p feature "mplex" (*)
    ├── libp2p feature "noise" (*)
    ├── libp2p feature "request-response" (*)
    └── libp2p feature "tcp-tokio" (*)
├── libp2p-core feature "default"
│   ├── libp2p-mplex v0.29.0
│   │   └── libp2p-mplex feature "default"
│   │       └── libp2p v0.39.1 (*)
│   ├── libp2p-noise v0.32.0
│   │   └── libp2p-noise feature "default"
│   │       └── libp2p v0.39.1 (*)
│   ├── libp2p-request-response v0.12.0
│   │   └── libp2p-request-response feature "default"
│   │       └── libp2p v0.39.1 (*)
│   ├── libp2p-swarm v0.30.0
│   │   └── libp2p-swarm feature "default"
│   │       ├── libp2p v0.39.1 (*)
│   │       └── libp2p-request-response v0.12.0 (*)
│   └── libp2p-tcp v0.29.0
│       └── libp2p v0.39.1 (*)
│       ├── libp2p-tcp feature "if-addrs"
│       │   └── libp2p-tcp feature "tokio"
│       │       └── libp2p feature "tcp-tokio" (*)
│       ├── libp2p-tcp feature "tokio" (*)
│       └── libp2p-tcp feature "tokio-crate"
│           └── libp2p-tcp feature "tokio" (*)
├── libp2p-core feature "libsecp256k1"
│   └── libp2p-core feature "secp256k1"
│       └── libp2p-core feature "default" (*)
└── libp2p-core feature "secp256k1" (*)

After this PR:

➜  sz git:(master) ✗ cargo tree -e features -i libp2p-core
libp2p-core v0.30.0-rc.2 (~/rust-libp2p/core)
├── libp2p v0.40.0-rc.3 (~/rust-libp2p)
│   ├── libp2p feature "libp2p-mplex"
│   │   └── libp2p feature "mplex"
│   │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz)
│   │           └── sz feature "default" (command-line)
│   ├── libp2p feature "libp2p-noise"
│   │   └── libp2p feature "noise"
│   │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz) (*)
│   ├── libp2p feature "libp2p-request-response"
│   │   └── libp2p feature "request-response"
│   │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz) (*)
│   ├── libp2p feature "libp2p-tcp"
│   │   └── libp2p feature "tcp-tokio"
│   │       └── sz v0.1.0 (/Users/bytedance/Documents/Temp/sz) (*)
│   ├── libp2p feature "mplex" (*)
│   ├── libp2p feature "noise" (*)
│   ├── libp2p feature "request-response" (*)
│   └── libp2p feature "tcp-tokio" (*)
├── libp2p-mplex v0.30.0-rc.1 (~/rust-libp2p/muxers/mplex)
│   └── libp2p v0.40.0-rc.3 (~/rust-libp2p) (*)
├── libp2p-noise v0.33.0-rc.1 (~/rust-libp2p/transports/noise)
│   └── libp2p v0.40.0-rc.3 (~/rust-libp2p) (*)
├── libp2p-request-response v0.13.0-rc.1 (~/rust-libp2p/protocols/request-response)
│   └── libp2p v0.40.0-rc.3 (~/rust-libp2p) (*)
├── libp2p-swarm v0.31.0-rc.2 (~/rust-libp2p/swarm)
│   └── libp2p-swarm feature "default"
│       ├── libp2p v0.40.0-rc.3 (~/rust-libp2p) (*)
│       └── libp2p-request-response v0.13.0-rc.1 (~/rust-libp2p/protocols/request-response) (*)
└── libp2p-tcp v0.30.0-rc.1 (~/rust-libp2p/transports/tcp)
    └── libp2p v0.40.0-rc.3 (~/rust-libp2p) (*)
    ├── libp2p-tcp feature "if-addrs"
    │   └── libp2p-tcp feature "tokio"
    │       └── libp2p feature "tcp-tokio" (*)
    ├── libp2p-tcp feature "tokio" (*)
    └── libp2p-tcp feature "tokio-crate"
        └── libp2p-tcp feature "tokio" (*)

[mxinden]

Thanks for the additional info. I can reproduce it on https://github.com/mxinden/libp2p-lookup now.

This is puzzling. Have you been able to find a corresponding bug report on cargo by any chance @name1e5s?

[folex]

#2437 is a fix for the features leak

[mxinden]

Closing here since I am having difficulties reproducing it. @name1e5s please comment in case you are still facing this issue.