Replace panic with graceful error returns in tmuxedit and mcp-server

Change initDebugLog() and defaultLogPath() to return errors instead of
panicking. Callers now handle errors gracefully with proper messages.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

2 files changed, 13 insertions, 6 deletions

diff --git a/cmd/hexai-mcp-server/main.go b/cmd/hexai-mcp-server/main.go
index 1f52616..32817f3 100644
--- a/cmd/hexai-mcp-server/main.go
+++ b/cmd/hexai-mcp-server/main.go
@@ -56,7 +56,11 @@ type mcpOptions struct {
 func main() {
 	printDeprecationWarning()
 
-	defaultLog := defaultLogPath()
+	defaultLog, err := defaultLogPath()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: %v\n", err)
+		os.Exit(1)
+	}
 	logPath := flag.String("log", defaultLog, "path to log file (optional)")
 	configPath := flag.String("config", "", "path to config file (optional)")
 	promptsDir := flag.String("prompts-dir", "", "path to prompts directory (optional)")
@@ -108,11 +112,11 @@ func run(opts mcpOptions, stdin io.Reader, stdout, stderr io.Writer) error {
 }
 
 // defaultLogPath returns the default MCP log file path in the state directory.
-// Panics if state directory cannot be created.
-func defaultLogPath() string {
+// Returns an error if the state directory cannot be created.
+func defaultLogPath() (string, error) {
 	stateDir, err := appconfig.StateDir()
 	if err != nil {
-		panic(fmt.Sprintf("cannot create state directory: %v", err))
+		return "", fmt.Errorf("cannot create state directory: %w", err)
 	}
-	return fmt.Sprintf("%s/hexai-mcp-server.log", stateDir)
+	return fmt.Sprintf("%s/hexai-mcp-server.log", stateDir), nil
 }
diff --git a/cmd/hexai-mcp-server/main_test.go b/cmd/hexai-mcp-server/main_test.go
index cf48954..76d0fca 100644
--- a/cmd/hexai-mcp-server/main_test.go
+++ b/cmd/hexai-mcp-server/main_test.go
@@ -41,7 +41,10 @@ func TestPrintDeprecationWarning(t *testing.T) {
 }
 
 func TestDefaultLogPath(t *testing.T) {
-	path := defaultLogPath()
+	path, err := defaultLogPath()
+	if err != nil {
+		t.Fatalf("defaultLogPath returned error: %v", err)
+	}
 	if path == "" {
 		t.Fatal("expected non-empty log path")
 	}