fix(execenv): clean stale Codex memories on env reuse (fixes #3130)

server/internal/daemon/execenv/codex_home.go

@@ -62,6 +62,15 @@ func prepareCodexHomeWithOpts(codexHome string, opts CodexHomeOptions, logger *s
 		return fmt.Errorf("create codex-home dir: %w", err)
 	}
 
+	// Remove stale Codex-generated memories from a prior task so the new
+	// task starts with a clean memory state. On the Prepare path the entire
+	// envRoot is already removed, so this is a harmless no-op; on the Reuse
+	// path (same agent+issue re-run) it prevents cross-task memory leakage
+	// (see #3130).
+	if err := os.RemoveAll(filepath.Join(codexHome, "memories")); err != nil {
+		logger.Warn("execenv: codex-home clean stale memories failed", "error", err)
+	}
+
 	// Symlink shared directories (sessions) so logs stay in the global home.
 	for _, name := range codexSymlinkedDirs {
 		src := filepath.Join(sharedHome, name)

server/internal/daemon/execenv/codex_home_memories_test.go

@@ -0,0 +1,60 @@
+package execenv
+
+import (
+	"log/slog"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestPrepareCodexHome_CleansStaleMemories(t *testing.T) {
+	dir := t.TempDir()
+
+	codexHome := filepath.Join(dir, "codex-home")
+	sharedHome := filepath.Join(dir, "shared-codex")
+
+	// Seed a shared ~/.codex/ so prepareCodexHomeWithOpts doesn't warn.
+	os.MkdirAll(sharedHome, 0o755)
+	t.Setenv("CODEX_HOME", sharedHome)
+
+	// First call — simulate a prior task that left memories behind.
+	if err := os.MkdirAll(filepath.Join(codexHome, "memories"), 0o755); err != nil {
+		t.Fatalf("seed memories dir: %v", err)
+	}
+	staleMemory := filepath.Join(codexHome, "memories", "raw_memories.md")
+	if err := os.WriteFile(staleMemory, []byte("cwd: D:\\OldProject\nthread: old-thread-id\n"), 0o644); err != nil {
+		t.Fatalf("seed stale memory: %v", err)
+	}
+
+	// Verify the stale file exists before prepare.
+	if _, err := os.Stat(staleMemory); err != nil {
+		t.Fatalf("stale memory should exist before prepare: %v", err)
+	}
+
+	// Run prepare — should clean stale memories.
+	logger := slog.Default()
+	if err := prepareCodexHome(codexHome, logger); err != nil {
+		t.Fatalf("prepareCodexHome: %v", err)
+	}
+
+	// Stale memories directory should be gone.
+	if _, err := os.Stat(filepath.Join(codexHome, "memories")); !os.IsNotExist(err) {
+		t.Errorf("expected memories dir to be removed after prepare, err: %v", err)
+	}
+}
+
+func TestPrepareCodexHome_NoMemoriesDir_NoError(t *testing.T) {
+	dir := t.TempDir()
+
+	codexHome := filepath.Join(dir, "codex-home")
+	sharedHome := filepath.Join(dir, "shared-codex")
+
+	os.MkdirAll(sharedHome, 0o755)
+	t.Setenv("CODEX_HOME", sharedHome)
+
+	// No memories directory exists — should not error.
+	logger := slog.Default()
+	if err := prepareCodexHome(codexHome, logger); err != nil {
+		t.Fatalf("prepareCodexHome: %v", err)
+	}
+}