Logging in Rust code not working (in unit tests?)

[clokep]

We use pyo3-log to get Rust logs into the Python logging framework; this seems to not work properly. If you put e.g. a warn!(...) then it doesn't print out anywhere.

We initialize the logging module in lib.rs:

synapse/rust/src/lib.rs

Line 23 in 42d261c

pyo3_log::init();

And we import the synapse rust code very early in the Synapse process:

synapse/synapse/__init__.py

Line 83 in dc37b68

check_rust_lib_up_to_date()

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I think we're importing the rust code before the loggers are configured, which then causes pyo3-log to initialize and cache the Python logging configuration, then by the time we actually call Rust code we've reconfigured the python loggers, but that doesn't propagate into Rust.

I ran into this in unittests, but I think it would happen during normal usage as well.

[clokep]

A potential solution might be to "re-initialize" the pyo3-log each time we reload the logging config?