tracing-subscriber depends on unicode case-insensitivity, but doesn't enable unicode-case feature

[jyn514]

Bug Report

Version

; cargo tree -i tracing
tracing v0.1.37
├── example v0.1.0 (/Users/jyn/src/example)
└── tracing-subscriber v0.2.25
    └── example v0.1.0 (/Users/jyn/src/example)

Platform

Darwin jyns-MacBook-Pro 22.4.0 Darwin Kernel Version 22.4.0: Mon Mar  6 20:59:28 PST 2023; root:xnu-8796.101.5~3/RELEASE_ARM64_T6000 arm64

Crates

tracing-subscriber

Description

Steps to reproduce:

1. cargo add tracing@0.1.37 --no-default-features --features std
2. cargo add tracing-subscriber@0.2.25

echo 'use tracing_subscriber::{EnvFilter, fmt, prelude::*};

fn main() {
    tracing_subscriber::registry()
    .with(fmt::layer())
    .with(EnvFilter::from_default_env())
    .init();
}' > src/main.rs

4. RUST_LOG=info cargo run

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Syntax(
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
regex parse error:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1: (?x)
 2:                 ^(?P<global_level>(?i:trace|debug|info|warn|error|off|[0-5]))$ |
                                          ^
 3:                  #                 ^^^.
 4:                  #                     `note: we match log level names case-insensitively
 5:                 ^
 6:                 (?: # target name or span name
 7:                     (?P<target>[\w:-]+)|(?P<span>\[[^\]]*\])
 8:                 ){1,2}
 9:                 (?: # level or nothing
10:                     =(?P<level>(?i:trace|debug|info|warn|error|off|[0-5]))?
11:                      #          ^^^.
12:                      #              `note: we match log level names case-insensitively
13:                 )?
14:                 $
15:                 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: Unicode-aware case insensitivity matching is not available (make sure the unicode-case feature is enabled)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
)', /Users/jyn/.local/lib/cargo/registry/src/index.crates.io-6f17d22bba15001f/tracing-subscriber-0.2.25/src/filter/env/directive.rs:167:14
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

As a workaround, cargo add regex --features unicode-case fixes the panic.

[hawkw]

This is fixed in tracing-sobscriber 0.3.17 --- see also #2565.

[hawkw]

Oh, I see that you're using an 0.2.x version of tracing-subscriber. Is there a reason you're not using 0.3.x?

We don't generally support older semver-incompatible versions of tracing-subscriber, so it's fairly unlikely that there will be a backport of the fix for this to v0.2 --- not because backporting would be particularly difficult, but we don't currently have infrastructure for releasing off of older versions.

[jyn514]

ah, gotcha! I don't recall why we're using 0.2, but I suspect it won't be too hard to upgrade. Thanks for the quick response :)

[hawkw]

My pleasure, glad I could help!