fix: log silently swallowed errors instead of discarding them (#915)

* fix: log silently swallowed errors instead of discarding them

Replace bare `let _ = fallible_call()` and `.unwrap_or_default()`
patterns with explicit error logging via tracing:

- warn level: user-visible state loss (config save, reload, GC failures)
- debug level: non-actionable info (state files, network checks, lock release)

This makes failures observable in debug.log without changing control flow.

Closes #914

* fix: revert dead-code match on load_all_instances

load_all_instances() always returns Ok (errors are swallowed internally),
so the Err(e) branch was unreachable dead code. Revert to the original
unwrap_or_default() until the function is fixed to propagate errors.

* fix: log gc_stale failure on test-notification path

Mirror the change at push.rs:623 so the analogous gc_stale call on the
SendOutcome::Gone branch of the test-notification handler also logs
failures instead of silently discarding them. Issue #914 listed both
sites; this picks up the one missed by the original commit.

---------

Co-authored-by: njbrake <[email protected]>
Co-authored-by: Nathan Brake (Mozilla.ai) <[email protected]>

Author: jerome-benoit

src/server/mod.rs

@@ -495,7 +495,9 @@ pub async fn start_server(config: ServerConfig<'_>) -> anyhow::Result<()> {
             // render the right transport label: "tunnel" for Cloudflare,
             // "tailscale" for Tailscale Funnel, "local" for local-only.
             let mode = format!("{}\n", handle.mode_label());
-            let _ = std::fs::write(app_dir.join("serve.mode"), mode);
+            if let Err(e) = std::fs::write(app_dir.join("serve.mode"), mode) {
+                tracing::debug!("Failed to write serve.mode: {e}");
+            }
         }
 
         // Start health monitor (uses CancellationToken internally)
@@ -554,7 +556,9 @@ pub async fn start_server(config: ServerConfig<'_>) -> anyhow::Result<()> {
                 contents.push('\n');
             }
             write_secret_file(&app_dir.join("serve.url"), &contents);
-            let _ = std::fs::write(app_dir.join("serve.mode"), "local\n");
+            if let Err(e) = std::fs::write(app_dir.join("serve.mode"), "local\n") {
+                tracing::debug!("Failed to write serve.mode: {e}");
+            }
         }
 
         None

src/server/push.rs

@@ -95,13 +95,17 @@ impl VapidKeypair {
         // Re-check: another process may have generated while we were
         // waiting for the lock.
         if path.exists() {
-            let _ = FileExt::unlock(&lock_file);
+            if let Err(e) = FileExt::unlock(&lock_file) {
+                tracing::debug!("Failed to release lock file: {e}");
+            }
             return Self::load(path);
         }
 
         let kp = Self::generate()?;
         kp.persist(path)?;
-        let _ = FileExt::unlock(&lock_file);
+        if let Err(e) = FileExt::unlock(&lock_file) {
+            tracing::debug!("Failed to release lock file: {e}");
+        }
         Ok(kp)
     }
 
@@ -620,7 +624,9 @@ async fn fire_due_pushes(
                 let outcome =
                     super::push_send::send_one(&client, push.as_ref(), &sub, &payload_clone).await;
                 if outcome == super::push_send::SendOutcome::Gone {
-                    let _ = push.store.gc_stale(&sub.endpoint, sub.generation).await;
+                    if let Err(e) = push.store.gc_stale(&sub.endpoint, sub.generation).await {
+                        tracing::warn!("Failed to GC stale push subscription: {e}");
+                    }
                 }
             });
         }
@@ -819,10 +825,13 @@ pub async fn test(
             // Best-effort GC; the result still reports gone=1 even if GC
             // races with a re-subscribe (that's what the generation
             // counter in gc_stale prevents).
-            let _ = push
+            if let Err(e) = push
                 .store
                 .gc_stale(&body.endpoint, subscription.generation)
-                .await;
+                .await
+            {
+                tracing::warn!("Failed to GC stale push subscription: {e}");
+            }
         }
     }
     Ok(Json(result))

src/tui/home/input.rs

@@ -232,7 +232,9 @@ impl HomeView {
                         crate::session::config::load_config().map(|c| c.unwrap_or_default())
                     {
                         config.app_state.has_acknowledged_agent_hooks = true;
-                        let _ = crate::session::config::save_config(&config);
+                        if let Err(e) = crate::session::config::save_config(&config) {
+                            tracing::warn!("Failed to save config: {e}");
+                        }
                     }
                     // Resume session creation
                     if let Some(data) = self.pending_hooks_install_data.take() {

src/tui/home/mod.rs

@@ -405,7 +405,9 @@ impl HomeView {
         }
         if !orphan_ids.is_empty() {
             tracing::info!("Cleaned up {} orphaned creating sessions", orphan_ids.len());
-            let _ = view.save();
+            if let Err(e) = view.save() {
+                tracing::warn!("Failed to save view state: {e}");
+            }
         }
 
         // Batch-sync instance IDs and captured session IDs to tmux hidden env
@@ -671,7 +673,9 @@ impl HomeView {
                 if let Err(e) = self.save() {
                     tracing::error!("Failed to save after deletion: {}", e);
                 }
-                let _ = self.reload();
+                if let Err(e) = self.reload() {
+                    tracing::warn!("Failed to reload session state: {e}");
+                }
             } else {
                 let error = result.error;
                 self.mutate_instance(&result.session_id, |inst| {
@@ -933,7 +937,9 @@ impl HomeView {
                     self.on_launch_hooks_ran.insert(session_id.clone());
                 }
 
-                let _ = self.reload();
+                if let Err(e) = self.reload() {
+                    tracing::warn!("Failed to reload session state: {e}");
+                }
                 self.new_dialog = None;
 
                 Some(session_id)
@@ -1136,7 +1142,9 @@ impl HomeView {
     fn save_list_width(&self) {
         if let Ok(mut config) = load_config().map(|c| c.unwrap_or_default()) {
             config.app_state.home_list_width = Some(self.list_width);
-            let _ = save_config(&config);
+            if let Err(e) = save_config(&config) {
+                tracing::warn!("Failed to save config: {e}");
+            }
         }
     }
 

src/tui/settings/mod.rs

@@ -128,7 +128,13 @@ impl SettingsView {
             .map(repo_config_to_profile)
             .unwrap_or_default();
 
-        let mut available_profiles = list_profiles().unwrap_or_default();
+        let mut available_profiles = match list_profiles() {
+            Ok(p) => p,
+            Err(e) => {
+                tracing::debug!("Failed to list profiles: {e}");
+                Vec::new()
+            }
+        };
         if !available_profiles.contains(&profile.to_string()) {
             available_profiles.push(profile.to_string());
             available_profiles.sort();

src/update/mod.rs

@@ -110,7 +110,13 @@ pub async fn check_for_update(current_version: &str, force: bool) -> Result<Upda
         .build()?;
 
     // Fetch all releases (includes body/release notes)
-    let releases = fetch_releases(&client).await.unwrap_or_default();
+    let releases = match fetch_releases(&client).await {
+        Ok(r) => r,
+        Err(e) => {
+            tracing::debug!("Failed to fetch releases: {e}");
+            Vec::new()
+        }
+    };
 
     let latest_version = releases
         .first()