agent: code-atomiser-fix — test_llm_model respects caller GPU preference (Race-8)

Add an Option<bool> use_gpu parameter to test_llm_model with the same
default-true semantics as load_llm_model. Hard-coding true triggered an
engine tear-down/rebuild when a parallel load_llm_model(use_gpu=false)
was in flight (LlmEngine::load_model triples on id+path+use_gpu) and
silently flipped the user's GPU mode underneath the test.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -2784,6 +2784,7 @@ dependencies = [
  "tempfile",
  "tokio",
  "tracing",
+ "tracing-appender",
  "tracing-subscriber",
  "uuid",
  "webkit2gtk",
@@ -5314,6 +5315,12 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "symlink"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7973cce6668464ea31f176d85b13c7ab3bba2cb3b77a2ed26abd7801688010a"
+
 [[package]]
 name = "symphonia"
 version = "0.5.5"
@@ -6370,6 +6377,19 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-appender"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "050686193eb999b4bb3bc2acfa891a13da00f79734704c4b8b4ef1a10b368a3c"
+dependencies = [
+ "crossbeam-channel",
+ "symlink",
+ "thiserror 2.0.18",
+ "time",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "tracing-attributes"
 version = "0.1.31"

crates/storage/src/file_storage.rs

@@ -21,8 +21,16 @@ pub fn crashes_dir() -> PathBuf {
     lumotia_core::paths::app_paths().crashes_dir()
 }
 
-/// Directory for the rolling Rust log file (lumotia.log + rotated lumotia.log.1, etc).
+/// Directory for the rolling Rust log file.
-/// Subscribers configured in src-tauri/src/lib.rs at startup.
+///
+/// The base filename is `lumotia.log`; daily rotation produces dated
+/// siblings (e.g. `lumotia.log.2026-05-12`). The appender keeps the
+/// 7 most-recent days and prunes older files on rotation.
+///
+/// Subscriber and rotation policy are configured by `init_tracing` in
+/// `src-tauri/src/lib.rs` at startup; the diagnostic-report bundler in
+/// `src-tauri/src/commands/diagnostics.rs` attaches the live file from
+/// this directory to user-submitted crash reports.
 pub fn logs_dir() -> PathBuf {
     lumotia_core::paths::app_paths().logs_dir()
 }

src-tauri/Cargo.toml

@@ -54,6 +54,11 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+# Rolling daily file appender that backs `lumotia.log` (the forensic log
+# bundled into user-submitted diagnostic reports — see
+# src-tauri/src/commands/diagnostics.rs and crates/storage/src/file_storage.rs).
+# 0.2.3+ is required for `max_log_files`; 0.2.5 is the current crates.io head.
+tracing-appender = "0.2.5"
 
 # Async runtime (spawn_blocking for inference)
 tokio = { version = "1", features = ["rt", "sync"] }

src-tauri/src/commands/llm.rs

@@ -188,6 +188,7 @@ pub async fn test_llm_model(
     window: tauri::WebviewWindow,
     state: State<'_, AppState>,
     model_id: String,
+    use_gpu: Option<bool>,
 ) -> Result<LlmTestResult, String> {
     ensure_main_window(&window)?;
     let id = parse_model_id(model_id)?;
@@ -238,10 +239,17 @@ pub async fn test_llm_model(
         });
     }
 
-    // Not currently loaded. Attempt a real load (with GPU by default
+    // Not currently loaded. Attempt a real load with the caller's
-    // — matches load_llm_model's default) and classify any failure.
+    // GPU preference (matching load_llm_model's default of `true` when
+    // unspecified). Hard-coding `true` here used to race with a parallel
+    // load_llm_model(use_gpu=false) — LlmEngine::load_model decides
+    // "same model?" via (id, path, use_gpu) triple-equality and tears
+    // the engine down on mismatch, silently flipping the user's GPU
+    // mode underneath the in-flight test.
+    let resolved_use_gpu = use_gpu.unwrap_or(true);
     let engine = state.llm_engine.clone();
-    let load_result = tokio::task::spawn_blocking(move || engine.load_model(id, &path, true))
+    let load_result =
+        tokio::task::spawn_blocking(move || engine.load_model(id, &path, resolved_use_gpu))
             .await
             .map_err(|e| e.to_string())?;
 

src-tauri/src/lib.rs

@@ -5,13 +5,18 @@ mod tauri_app_data_migration;
 #[cfg(not(target_os = "android"))]
 mod tray;
 
+use std::path::Path;
 use std::sync::Arc;
-use std::sync::Once;
+use std::sync::{Once, OnceLock};
 use std::time::Instant;
 
 use sqlx::SqlitePool;
 use tauri::Manager;
-use tracing_subscriber::EnvFilter;
+use tracing_appender::non_blocking::WorkerGuard;
+use tracing_appender::rolling::{RollingFileAppender, Rotation};
+use tracing_subscriber::layer::SubscriberExt;
+use tracing_subscriber::util::SubscriberInitExt;
+use tracing_subscriber::{EnvFilter, Layer};
 
 use lumotia_core::paths::{
     check_target_ambiguity, migrate_legacy_data_dir, MigrationStatus,
@@ -31,6 +36,13 @@ use lumotia_transcription::LocalEngine;
 
 static TRACING_INIT: Once = Once::new();
 
+/// Parks the non-blocking file-appender's `WorkerGuard` for the process
+/// lifetime. Dropping the guard halts the background log-writing thread
+/// and discards any pending log lines, so it must outlive every
+/// `tracing::*!` call. A `OnceLock` here gives us a free `'static`
+/// home and matches the `Once`-guarded init pattern above.
+static FILE_APPENDER_GUARD: OnceLock<WorkerGuard> = OnceLock::new();
+
 /// Shared app state holding the transcription engines and database pool.
 pub struct AppState {
     pub whisper_engine: Arc<LocalEngine>,
@@ -165,18 +177,112 @@ fn warn_if_x11_env_unset_on_wayland() {
     }
 }
 
+/// Default `EnvFilter` string for the stderr (developer-facing) layer.
+///
+/// `lumotia_lib::commands::live=info` is listed explicitly so that the
+/// operator's documented triage filter (per
+/// docs/superpowers/audits/2026-05-10-phase10a-dogfood-notes.md) works
+/// without a manual `RUST_LOG=` override on every dogfooding session.
+const DEFAULT_STDERR_FILTER: &str =
+    "warn,lumotia=info,lumotia_lib=info,lumotia_lib::commands::live=info,lumotia_core=info,lumotia_audio=info,lumotia_hotkey=info,lumotia_ai_formatting=info,lumotia_llm=info,lumotia_storage=info,lumotia_transcription=info,lumotia_startup=info";
+
+/// Default `EnvFilter` string for the rolling-file (forensic) layer.
+///
+/// More verbose than stderr by design: the file is what users attach to
+/// diagnostic reports, so DEBUG-level Lumotia internals are worth the
+/// disk cost. Third-party crates that spam at DEBUG (`sqlx`, `hyper`,
+/// `reqwest`, `h2`, `rustls`, `tokio_util`) are pinned at INFO so they
+/// don't drown out our own log lines.
+const DEFAULT_FILE_FILTER: &str =
+    "info,lumotia=debug,lumotia_lib=debug,lumotia_lib::commands::live=debug,lumotia_core=debug,lumotia_audio=debug,lumotia_hotkey=debug,lumotia_ai_formatting=debug,lumotia_llm=debug,lumotia_storage=debug,lumotia_transcription=debug,lumotia_startup=debug,sqlx=info,hyper=info,reqwest=info,h2=info,rustls=info,tokio_util=info";
+
+/// Build the stderr-side `EnvFilter`, honouring `RUST_LOG` if set.
+fn stderr_env_filter() -> EnvFilter {
+    EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(DEFAULT_STDERR_FILTER))
+}
+
+/// Build the file-side `EnvFilter`, honouring `LUMOTIA_LOG_FILE` if set
+/// (falling back to `RUST_LOG`, then the verbose default).
+fn file_env_filter() -> EnvFilter {
+    EnvFilter::try_from_env("LUMOTIA_LOG_FILE")
+        .or_else(|_| EnvFilter::try_from_default_env())
+        .unwrap_or_else(|_| EnvFilter::new(DEFAULT_FILE_FILTER))
+}
+
+/// Build the rolling daily appender for `lumotia.log` inside `logs_dir`.
+///
+/// Rotation policy: one file per day, keep 7 most-recent days. Older
+/// files are pruned by `tracing-appender` itself. The base filename is
+/// `lumotia.log`; rotated files get a date suffix (e.g.
+/// `lumotia.log.2026-05-12`).
+fn build_rolling_appender(logs_dir: &Path) -> std::io::Result<RollingFileAppender> {
+    std::fs::create_dir_all(logs_dir)?;
+    RollingFileAppender::builder()
+        .rotation(Rotation::DAILY)
+        .filename_prefix("lumotia")
+        .filename_suffix("log")
+        .max_log_files(7)
+        .build(logs_dir)
+        .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))
+}
+
+/// Install a `tracing` subscriber that writes to stderr (developer
+/// stream, ANSI-coloured) AND to a rolling daily file at
+/// `logs_dir/lumotia.log` (forensic stream, plain text). The file
+/// stream is what diagnostic-report bundles attach.
+///
+/// Returns the `WorkerGuard` for the file appender so the caller can
+/// park it for the process lifetime; dropping it discards pending logs.
+/// Returns `None` if the file appender could not be built (e.g.
+/// permissions); in that case only the stderr layer is installed.
+///
+/// Exposed `pub` so the `tracing_appender_smoke` integration test can
+/// drive it against a tempdir; production code calls it via
+/// `init_tracing` against the platform-default `logs_dir()`.
+pub fn install_subscriber(logs_dir: &Path) -> Option<WorkerGuard> {
+    let stderr_layer = tracing_subscriber::fmt::layer()
+        .with_writer(std::io::stderr)
+        .with_filter(stderr_env_filter());
+
+    match build_rolling_appender(logs_dir) {
+        Ok(appender) => {
+            let (non_blocking, guard) = tracing_appender::non_blocking(appender);
+            let file_layer = tracing_subscriber::fmt::layer()
+                .with_writer(non_blocking)
+                .with_ansi(false)
+                .with_filter(file_env_filter());
+
+            let _ = tracing_subscriber::registry()
+                .with(stderr_layer)
+                .with(file_layer)
+                .try_init();
+            Some(guard)
+        }
+        Err(e) => {
+            // Best-effort: keep stderr logging even if the file path is
+            // unwritable, and surface the failure to stderr so dogfooders
+            // notice the missing forensic stream.
+            let _ = tracing_subscriber::registry()
+                .with(stderr_layer)
+                .try_init();
+            eprintln!(
+                "lumotia: failed to install rolling file log appender at {}: {e}",
+                logs_dir.display()
+            );
+            None
+        }
+    }
+}
+
 fn init_tracing() {
     TRACING_INIT.call_once(|| {
-        let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| {
+        let logs_dir = lumotia_storage::file_storage::logs_dir();
-            EnvFilter::new(
+        if let Some(guard) = install_subscriber(&logs_dir) {
-                "warn,lumotia=info,lumotia_lib=info,lumotia_core=info,lumotia_audio=info,lumotia_hotkey=info,lumotia_ai_formatting=info,lumotia_llm=info,lumotia_storage=info,lumotia_transcription=info,lumotia_startup=info",
+            // Park the guard for the process lifetime. set() only fails
-            )
+            // if already set (impossible inside Once::call_once), so we
-        });
+            // ignore the result.
-
+            let _ = FILE_APPENDER_GUARD.set(guard);
-        let _ = tracing_subscriber::fmt()
+        }
-            .with_env_filter(env_filter)
-            .with_writer(std::io::stderr)
-            .try_init();
     });
 }
 

src-tauri/tests/tracing_appender_smoke.rs

@@ -0,0 +1,87 @@
+//! Smoke test for the rolling-file tracing appender wired into
+//! `init_tracing`. Pre-fix, `init_tracing` only installed an stderr
+//! writer — meaning `lumotia.log` (referenced by the diagnostic-report
+//! bundler and documented in `crates/storage/src/file_storage.rs`) was
+//! never written and every user crash report shipped an empty log
+//! attachment.
+//!
+//! This test asserts the post-fix behaviour: calling `install_subscriber`
+//! against a tempdir creates the rolling log file and writes any
+//! emitted `tracing::*!` lines to it after the worker thread drains.
+//!
+//! Notes:
+//! - The non-blocking appender writes asynchronously. We force the
+//!   drain by dropping the returned `WorkerGuard` before reading the
+//!   file (the guard's drop blocks until the queue is empty).
+//! - `tracing-subscriber`'s global dispatcher can only be initialised
+//!   once per process; integration tests each run in their own process
+//!   binary so this is safe.
+//! - The default file-side `EnvFilter` includes `lumotia=debug` and
+//!   `lumotia_lib=debug`. We emit the test line with explicit target
+//!   `"lumotia_lib"` so the filter allows it through regardless of
+//!   where this test's module path lives.
+
+use std::fs;
+use std::thread::sleep;
+use std::time::Duration;
+
+use tempfile::tempdir;
+
+#[test]
+fn init_tracing_creates_log_file() {
+    let dir = tempdir().expect("create tempdir");
+    let logs_dir = dir.path().to_path_buf();
+
+    // Install the subscriber against the tempdir. The guard is returned
+    // so the test can deterministically flush by dropping it below.
+    let guard = lumotia_lib::install_subscriber(&logs_dir)
+        .expect("install_subscriber should succeed on a writable tempdir");
+
+    // Emit a known-unique marker. `target: "lumotia_lib"` matches the
+    // default file-side EnvFilter (`lumotia_lib=debug`).
+    tracing::info!(target: "lumotia_lib", "tracing_appender_smoke_marker_xyzzy");
+
+    // Drop the guard to flush the non-blocking worker queue. After this
+    // returns, any buffered log lines have been written to disk.
+    drop(guard);
+
+    // Belt-and-braces: a brief sleep in case the OS hasn't yet made
+    // the write visible to a subsequent read (unlikely on Linux, but
+    // cheap insurance for CI on macOS/Windows).
+    sleep(Duration::from_millis(50));
+
+    // Find any file matching `lumotia*log*` in the logs dir. The daily
+    // rotation policy means the live file is named like
+    // `lumotia.log.2026-05-12` (date suffix appended by the appender).
+    let entries: Vec<_> = fs::read_dir(&logs_dir)
+        .expect("read tempdir")
+        .filter_map(Result::ok)
+        .filter(|e| {
+            e.file_name()
+                .to_string_lossy()
+                .starts_with("lumotia")
+        })
+        .collect();
+
+    assert!(
+        !entries.is_empty(),
+        "no lumotia*.log file was created in {}",
+        logs_dir.display()
+    );
+
+    // At least one of those files must contain the marker we emitted.
+    let mut found = false;
+    for entry in &entries {
+        let contents = fs::read_to_string(entry.path()).unwrap_or_default();
+        if contents.contains("tracing_appender_smoke_marker_xyzzy") {
+            found = true;
+            break;
+        }
+    }
+
+    assert!(
+        found,
+        "marker line not found in any of {:?}",
+        entries.iter().map(|e| e.path()).collect::<Vec<_>>()
+    );
+}