feat: enable tabby to print debug logs

[costanzo]

Add --enable-debug flag so tabby will print debug logs.

[wsxiaoys]

You could enable debug log by setting

RUST_LOG=debug tabby ...

Maybe just add this to FAQ?

[costanzo]

I have tried the RUST_LOG=debug eviroment flag. Indeed some modules' debug logs are enabled but the tabby debug log itself is not enabled. Because it forced to INFO here crates/tabby/src/main.rs:

...
.add_directive("tabby=info".parse().unwrap())
...

I am not sure why it is set INFO here but maybe we can remove that and accept the RUST_LOG environment flag to control?

[wsxiaoys]

I am not sure why it is set INFO here but maybe we can remove that and accept the RUST_LOG environment flag to control?

The goal is to enable default info-level logging for the Tabby package. Perhaps we can implement a check to prevent the acceptance of a more verbose environment variable override, such as RUST_LOG=tabby=debug.

[costanzo]

Oh, I just realized the default tracing log level is ERROR not INFO if RUST_LOG is not set.

Perhaps we can implement a check to prevent the acceptance of a more verbose environment variable override, such as RUST_LOG=tabby=debug

Why do we need to avoid a verbose environment variable override. I mean we definitely need to print debug logs in Tabby package, right?

[wsxiaoys]

Perhaps we can implement a check to prevent the acceptance of a more verbose environment variable override, such as RUST_LOG=tabby=debug

Why do we need to avoid a verbose environment variable override. I mean we definitely need to print debug logs in Tabby package, right?

To avoid pretenting the acceptance :)

Based on https://docs.rs/tracing-subscriber/latest/src/tracing_subscriber/filter/env/builder.rs.html#69

A proper implementation would be

let filter = EnvFilter::builder()
     .with_default_directive(LevelFilter::ERROR.into())
     .parse_lossy("tabby=info")
     ...
     .from_env_lossy()

[costanzo]

Hi @wsxiaoys if I am understanding correctly, we want to set the default log level to be error, and set default tabby log level to be info. At the same time we want the envrionment log settings to be able to override the default tabby log level?

I check the tracing-subscriber doc and find there is no way of doing that.

parse_lossy method will return an EnvFilter, which will no longer parse env.

So I just set default directive to be LevelFilter::INFO which can enable Tabby pacakge logging. And info log in other packages is helpful for various purposes.

[wsxiaoys]

I think it's still doable - though you might need dig into the implementation of EnvFilter a bit.

[wsxiaoys]

This is done recently:

tabby/crates/tabby/src/main.rs

Line 223 in 24c544c

let mut dirs = "tabby=info,axum_tracing_opentelemetry=info,otel=debug".to_owned();