chore(apple): initiate logging subscriber as early as possible (#4143)

Also, return error with tracing subscriber initialization

rust/connlib/clients/apple/src/lib.rs

@@ -14,8 +14,8 @@ use std::{
     time::Duration,
 };
 use tokio::runtime::Runtime;
-use tracing_subscriber::prelude::*;
 use tracing_subscriber::EnvFilter;
+use tracing_subscriber::{prelude::*, util::TryInitError};
 
 /// The Apple client implements reconnect logic in the upper layer using OS provided
 /// APIs to detect network connectivity changes. The reconnect timeout here only
@@ -168,18 +168,18 @@ impl Callbacks for CallbackHandler {
     }
 }
 
-fn init_logging(log_dir: PathBuf, log_filter: String) -> file_logger::Handle {
+fn init_logging(log_dir: PathBuf, log_filter: String) -> Result<file_logger::Handle, TryInitError> {
     let (file_layer, handle) = file_logger::layer(&log_dir);
 
-    let _ = tracing_subscriber::registry()
+    tracing_subscriber::registry()
         .with(
             tracing_oslog::OsLogger::new("dev.firezone.firezone", "connlib")
                 .with_filter(EnvFilter::new(log_filter.clone())),
         )
         .with(file_layer.with_filter(EnvFilter::new(log_filter)))
-        .try_init();
+        .try_init()?;
 
-    handle
+    Ok(handle)
 }
 
 impl WrappedSession {
@@ -196,6 +196,7 @@ impl WrappedSession {
         log_filter: String,
         callback_handler: ffi::CallbackHandler,
     ) -> Result<Self, String> {
+        let handle = init_logging(log_dir.into(), log_filter).map_err(|e| e.to_string())?;
         let secret = SecretString::from(token);
 
         let (private_key, public_key) = keypair();
@@ -219,7 +220,7 @@ impl WrappedSession {
             os_version_override,
             CallbackHandler {
                 inner: Arc::new(callback_handler),
-                handle: init_logging(log_dir.into(), log_filter),
+                handle,
             },
             Some(MAX_PARTITION_TIME),
             runtime.handle().clone(),