the env-filter feature is not additive

[lolbinarycat]

Bug Report

Version

│   │   │   └── tracing v0.1.40
│   │   │       ├── tracing-attributes v0.1.27 (proc-macro)
│   │   │       └── tracing-core v0.1.32
├── tracing v0.1.40 (*)
└── tracing-subscriber v0.3.18
    ├── tracing v0.1.40 (*)
    ├── tracing-core v0.1.32 (*)
    └── tracing-log v0.2.0
        └── tracing-core v0.1.32 (*)
└── tracing-subscriber v0.3.18 (*)

Platform

Linux blueberry 6.8.12 #1-NixOS SMP PREEMPT_DYNAMIC Thu May 30 07:49:53 UTC 2024 x86_64 GNU/Linux

Crates

tracing_subscriber

Description

cargo features should be strictly additive, but env-filter changes the behavior of tracing_subscriber::fmt::init in a way that is not fully documented. worse, replicating the behavior of tracing_subscriber::fmt::init in a way that doesn't change depending on what features are enabled is non-trivial and requires several extra imports, as well as reading the source code.