disable tracing-log feature for tracing-subscriber

[konradsz]

What was changed

Disable the tracing-log feature for tracing-subscriber by turning off default features. The ansi feature was explicitly listed because it's used in the code.

Why?

I am trying to use core crate from Temporal SDK in a Rust application that already uses tracing-subscriber. However, it fails to initialize the subscriber because core depends on tracing-subscriber with tracing-log feature enabled. This behavior is documented here:

This method panics if a global default subscriber has already been set, or if a log logger has already been set (when the “tracing-log” feature is enabled).

In a perfect world, core would not depend on tracing-subscribers since it is a library, but I propose this as an immediate fix.

[CLAassistant]

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[Sushisource]

Thanks for this @konradsz . I think this is left-over from when log was used internally too.

And yes, I agree about

In a perfect world, core would not depend on tracing-subscribers

In principle, but Core is in a bit of an odd position where most consumers are using FFI and so a lot of the time logging needs to be enabled by the library itself too. Potentially we could introduce another crate that thinly layers over core by adding the tracing subscriber dep and maybe a handful of other things meant for non-Rust consumers, but that's for another day.

Thanks!