fix(v0.9.2): serialize CLAUDE_CONFIG_DIR mutation in discovery tests

Windows CI runner failed v0.9.1 release because four tests in
session::discovery::tests mutated CLAUDE_CONFIG_DIR concurrently
and observed each other's writes. Symptom:
  assertion `left == right` failed
    left: "C:\\Users\\runneradmin\\.claude"
    right: "/tmp/custom-claude-config"

Fix: module-level `static ENV_LOCK: Mutex<()> = Mutex::new(());`
acquired at the top of every test that touches CLAUDE_CONFIG_DIR.
Also: claude_config_dir_handles_env_var uses std::env::temp_dir()
for a portable path instead of hardcoded /tmp/... which doesn't
exist on Windows.

Linux + macOS passed silently — the race existed there too but the
particular scheduling order didn't trip it. The mutex prevents the
race on every platform.

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

Author: Shahinyanm

CHANGELOG.md

@@ -7,6 +7,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.9.2] - 2026-05-17
+
+### Fixed
+- Windows CI flake in `session::discovery::tests::*` — four tests
+  mutated `CLAUDE_CONFIG_DIR` in parallel and observed each other's
+  writes. Now serialized through a module-level `Mutex<()>`; the
+  Windows runner sees the expected override path. Linux/macOS were
+  asymptomatically affected by the same race.
+- `claude_config_dir_respects_env_var` no longer hardcodes
+  `/tmp/custom-claude-config` (invalid on Windows). Uses
+  `std::env::temp_dir()` for a portable path.
+
 ## [0.9.1] - 2026-05-17
 
 ### Fixed

Cargo.lock

@@ -7,7 +7,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.9.1"
+version = "0.9.2"
 edition = "2021"
 rust-version = "1.88"
 license = "MIT"

Cargo.toml

@@ -16,7 +16,7 @@ name = "task-journal"
 path = "src/main.rs"
 
 [dependencies]
-tj-core = { package = "task-journal-core", version = "0.9.1", path = "../tj-core" }
+tj-core = { package = "task-journal-core", version = "0.9.2", path = "../tj-core" }
 anyhow = { workspace = true }
 clap = { workspace = true }
 tracing = { workspace = true }

crates/tj-cli/Cargo.toml

@@ -136,6 +136,16 @@ fn dirs_home() -> anyhow::Result<PathBuf> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::sync::Mutex;
+
+    /// Serialize every test that touches `CLAUDE_CONFIG_DIR`. Cargo runs
+    /// unit tests in parallel by default; two tests mutating the same
+    /// process env race (set in A, observed in B) and flaked Windows CI
+    /// (saw "C:\Users\runneradmin\.claude" when expecting the override).
+    /// Tests that touch the env take this lock before the first set_var.
+    /// `lock().unwrap_or_else(|p| p.into_inner())` swallows poisoning
+    /// from a panicking sibling test — env is restored regardless.
+    static ENV_LOCK: Mutex<()> = Mutex::new(());
 
     #[test]
     fn encode_path_replaces_separators() {
@@ -257,6 +267,7 @@ mod tests {
 
     #[test]
     fn find_project_dir_with_env_override() {
+        let _g = ENV_LOCK.lock().unwrap_or_else(|p| p.into_inner());
         let dir = tempfile::tempdir().unwrap();
         let projects = dir.path().join("projects");
         std::fs::create_dir_all(&projects).unwrap();
@@ -281,6 +292,7 @@ mod tests {
 
     #[test]
     fn find_project_dir_returns_none_when_no_match() {
+        let _g = ENV_LOCK.lock().unwrap_or_else(|p| p.into_inner());
         let dir = tempfile::tempdir().unwrap();
         let projects = dir.path().join("projects");
         std::fs::create_dir_all(&projects).unwrap();
@@ -296,6 +308,7 @@ mod tests {
 
     #[test]
     fn find_project_dir_returns_none_when_projects_dir_missing() {
+        let _g = ENV_LOCK.lock().unwrap_or_else(|p| p.into_inner());
         let dir = tempfile::tempdir().unwrap();
         // Don't create a "projects" subdir — it doesn't exist.
 
@@ -319,20 +332,46 @@ mod tests {
 
     // --- claude_config_dir ---
 
+    /// Both `CLAUDE_CONFIG_DIR` cases are combined into one test so the
+    /// env-var read/write/restore steps run serially. Cargo runs unit
+    /// tests in parallel by default; two tests touching the same process
+    /// env on Windows raced (set in test A, observed in test B) and
+    /// flaked CI. Save → set → assert → restore inside one body makes
+    /// the dependency local. Uses a portable tempdir-style path rather
+    /// than the hardcoded "/tmp/..." that doesn't exist on Windows.
     #[test]
-    fn claude_config_dir_respects_env_var() {
-        std::env::set_var("CLAUDE_CONFIG_DIR", "/tmp/custom-claude-config");
+    fn claude_config_dir_handles_env_var() {
+        let _g = ENV_LOCK.lock().unwrap_or_else(|p| p.into_inner());
+        // SAFETY: the ENV_LOCK above serializes us against the other
+        // CLAUDE_CONFIG_DIR tests in this module; prev → restore at
+        // the end gives a clean exit regardless of panic.
+        let prev = std::env::var_os("CLAUDE_CONFIG_DIR");
+
+        // Case 1: non-empty value is honored verbatim. Use a portable
+        // path (std::env::temp_dir() works on Linux/macOS/Windows).
+        let custom = std::env::temp_dir().join("tj-custom-claude-config");
+        unsafe {
+            std::env::set_var("CLAUDE_CONFIG_DIR", &custom);
+        }
         let dir = claude_config_dir().unwrap();
-        std::env::remove_var("CLAUDE_CONFIG_DIR");
-        assert_eq!(dir, PathBuf::from("/tmp/custom-claude-config"));
-    }
+        assert_eq!(dir, custom);
 
-    #[test]
-    fn claude_config_dir_ignores_empty_env_var() {
-        std::env::set_var("CLAUDE_CONFIG_DIR", "");
+        // Case 2: empty value falls back to home + .claude.
+        unsafe {
+            std::env::set_var("CLAUDE_CONFIG_DIR", "");
+        }
         let dir = claude_config_dir().unwrap();
-        std::env::remove_var("CLAUDE_CONFIG_DIR");
-        // Should fall back to home dir + .claude.
-        assert!(dir.to_string_lossy().ends_with(".claude"));
+        assert!(
+            dir.to_string_lossy().ends_with(".claude"),
+            "fallback must land in <home>/.claude, got: {dir:?}"
+        );
+
+        // Restore.
+        unsafe {
+            match prev {
+                Some(v) => std::env::set_var("CLAUDE_CONFIG_DIR", v),
+                None => std::env::remove_var("CLAUDE_CONFIG_DIR"),
+            }
+        }
     }
 }

crates/tj-core/src/session/discovery.rs

@@ -16,7 +16,7 @@ name = "task-journal-mcp"
 path = "src/main.rs"
 
 [dependencies]
-tj-core = { package = "task-journal-core", version = "0.9.1", path = "../tj-core" }
+tj-core = { package = "task-journal-core", version = "0.9.2", path = "../tj-core" }
 anyhow = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }

crates/tj-mcp/Cargo.toml

@@ -1,6 +1,6 @@
 {
   "name": "task-journal",
-  "version": "0.9.1",
+  "version": "0.9.2",
   "description": "Append-only journal of AI-coding task reasoning chains: hypotheses, decisions, rejections, evidence. Renders compact resume packs so an agent can pick up a 2-week-old task with full context.",
   "author": {
     "name": "Mher Shahinyan"

plugin/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "task-journal",
-  "version": "0.9.1",
+  "version": "0.9.2",
   "description": "Append-only journal of AI-coding task reasoning chains. Captures hypotheses, decisions, rejections, evidence — renders compact resume packs so an agent can pick up a 2-week-old task with full context.",
   "author": {
     "name": "Mher Shahinyan",