docs: independent logging setup for testing

packages/test-helpers/src/configuration.rs

@@ -29,6 +29,11 @@ pub fn ephemeral() -> Configuration {
 
     let mut config = Configuration::default();
 
+    // This have to be Off otherwise the tracing global subscriber
+    // initialization will panic because you can't set a global subscriber more
+    // than once. You can use enable logging in tests with:
+    // `crate::common::logging::setup(LevelFilter::ERROR);`
+    // That will also allow you to capture logs and write assertions on them.
     config.logging.threshold = Threshold::Off;
 
     // Ephemeral socket address for API