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usage.rs minimal example does not print info event, no span trace either

Open fleetingbytes opened this issue 2 years ago • 2 comments

When I copy paste the source code of usage.rs into a new minimal rust project, it does not show the INFO trace event and the error does not have the SPANTRACE section.

The Cargo.toml of that minimal project looks like this:

[package]
name = "minimal"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
color-eyre = {version = "0.6.2", features = ["capture-spantrace"]}
tracing = "0.1.36"
tracing-subscriber = "0.3.15"
tracing-error = "0.2.0"

But when I run cargo run --example usage in the local clone of the color-eyre repository, I see the Info Event being print out just just fine:

2022-08-16T06:47:07.017504Z  INFO read_config:read_file{path="fake_file"}: Reading file

And the Error is shown with its span trace section:

...
  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ SPANTRACE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

   0: usage::read_file with path="fake_file"
      at examples\usage.rs:32
   1: usage::read_config
      at examples\usage.rs:38
...

What am I missing in the minimal example?

fleetingbytes avatar Aug 16 '22 07:08 fleetingbytes

If you copy the source text directly, then you'll include the #[cfg(feature = "capture-spantrace")], which won't work unless you've defined your own feature named the same. Try removing the directives, i.e. write this:

use color_eyre::{eyre::Report, eyre::WrapErr, Section};
use tracing::{info, instrument};

#[instrument]
fn main() -> Result<(), Report> {
    install_tracing();

    color_eyre::install()?;

    read_config()
}

fn install_tracing() {
    use tracing_error::ErrorLayer;
    use tracing_subscriber::prelude::*;
    use tracing_subscriber::{fmt, EnvFilter};

    let fmt_layer = fmt::layer().with_target(false);
    let filter_layer = EnvFilter::try_from_default_env()
        .or_else(|_| EnvFilter::try_new("info"))
        .unwrap();

    tracing_subscriber::registry()
        .with(filter_layer)
        .with(fmt_layer)
        .with(ErrorLayer::default())
        .init();
}

#[instrument]
fn read_file(path: &str) -> Result<(), Report> {
    info!("Reading file");
    Ok(std::fs::read_to_string(path).map(drop)?)
}

#[instrument]
fn read_config() -> Result<(), Report> {
    read_file("fake_file")
        .wrap_err("Unable to read config")
        .suggestion("try using a file that exists next time")
}

And then also enable the env-filter feature of tracing-subscriber so that the code builds:

[package]
name = "minimal"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
color-eyre = {version = "0.6.2", features = ["capture-spantrace"]}
tracing = "0.1.36"
tracing-subscriber = { version = "0.3.15", features = ["env-filter"] }
tracing-error = "0.2.0"

Then it works for me.

arxanas avatar Aug 29 '22 20:08 arxanas

Thanks, I'll check it out in the course of the next week.

fleetingbytes avatar Aug 31 '22 07:08 fleetingbytes