Add detailed logging to process holder

lib/src/action/process_holder.rs

@@ -1,6 +1,7 @@
 use std::sync::Arc;
 
 use tokio::sync::RwLock;
+use tracing::trace;
 
 use crate::{command::Supervisor, error::RuntimeError, signal::process::SubSignal};
 
@@ -21,31 +22,50 @@ impl ProcessHolder {
 	}
 
 	pub async fn drop_inner(&self) {
+		trace!("dropping supervisor");
 		self.0.write().await.take();
+		trace!("dropped supervisor");
 	}
 
 	pub async fn replace(&self, new: Supervisor) {
+		trace!("replacing supervisor");
 		if let Some(_old) = self.0.write().await.replace(new) {
+			trace!("replaced supervisor");
 			// TODO: figure out what to do with old
+		} else {
+			trace!("not replaced: no supervisor");
 		}
 	}
 
 	pub async fn signal(&self, sig: SubSignal) {
 		if let Some(p) = self.0.read().await.as_ref() {
+			trace!("signaling supervisor");
 			p.signal(sig).await;
+			trace!("signaled supervisor");
+		} else {
+			trace!("not signaling: no supervisor");
 		}
 	}
 
 	pub async fn kill(&self) {
 		if let Some(p) = self.0.read().await.as_ref() {
+			trace!("killing supervisor");
 			p.kill().await;
+			trace!("killed supervisor");
+		} else {
+			trace!("not killing: no supervisor");
 		}
 	}
 
 	pub async fn wait(&self) -> Result<(), RuntimeError> {
 		if let Some(p) = self.0.read().await.as_ref() {
+			trace!("waiting on supervisor");
 			p.wait().await?;
+			trace!("waited on supervisor");
+		} else {
+			trace!("not waiting: no supervisor");
 		}
-			Ok(())
+
+		Ok(())
 	}
 }