Using reload::Layer with a Filtered layer makes it possible to activate different tracing levels for various modules dynamically. However, it's not currently possible to modify the currently span event configuration since with_span_events can only be set when creating the layer. Due to #1629 it's not possible to completely re-load a layer and so span config is essentially set-once.
Solution
This PR adds a method similar to set_ansi to allow modifying the fmt span configuration in a call to reload::Handle::modify
Motivation
Using reload::Layer with a Filtered layer makes it possible to activate different tracing levels for various modules dynamically. However, it's not currently possible to modify the currently span event configuration since with_span_events can only be set when creating the layer. Due to #1629 it's not possible to completely re-load a layer and so span config is essentially set-once.
Solution
This PR adds a method similar to
set_ansito allow modifying the fmt span configuration in a call toreload::Handle::modifyCloses #2957