From e453f9aad97aa5d77cb14101d758c421827e6cac Mon Sep 17 00:00:00 2001
From: Amr Gharbeia <amr@gharbeia.net>
Date: Thu, 14 May 2026 15:57:37 -0400
Subject: [PATCH] fix: use global vars for cat subprocess to avoid let* scope
 crash

Replaced (let* ((cat-proc ...) (tty-in ...)) ...) with global
special variables *cat-proc* and *tty-in* with defvar declarations.
The let* caused 'unbound variable' errors on Ctrl+Q because the
lexical scope didn't extend to terminate-process. Global vars have
indefinite scope and work reliably regardless of paren nesting.
---
 org/channel-tui-main.org | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/org/channel-tui-main.org b/org/channel-tui-main.org
index 421316d..b3129c0 100644
--- a/org/channel-tui-main.org
+++ b/org/channel-tui-main.org
@@ -886,6 +886,9 @@ Event handlers + daemon I/O + main loop.
     (:down (lambda (e) (declare (ignore e)) (on-key :down)))
     (:escape (lambda (e) (declare (ignore e)) (on-key :escape)))))
 
+(defvar *cat-proc* nil "Cat subprocess for keyboard input")
+(defvar *tty-in* nil "Stream from cat subprocess stdout")
+
 (defun tui-main ()
   (init-state)
   (load-history)
@@ -912,12 +915,14 @@ Event handlers + daemon I/O + main loop.
         ;; bytes through a pipe that SBCL reads reliably.
          ;; stty -icanon -echo is set by the bash script before exec sbcl.
          ;; A cat subprocess reads keyboard input from the terminal.
-         (let* ((cat-proc (uiop:launch-program '("cat")
+          ;; Global vars for cat subprocess — avoid lexical let* scope issue
+          (progn
+            (setq *cat-proc* (uiop:launch-program '("cat")
                                               :output :stream
                                               :input :interactive
-                                              :stderr nil))
-               (tty-in (uiop:process-info-output cat-proc)))
-          (add-msg :system (format nil "* cat pid=~a *" (uiop:process-info-pid cat-proc)))
+                                              :stderr nil)
+                  *tty-in* (uiop:process-info-output *cat-proc*)))
+          (add-msg :system (format nil "* cat pid=~a *" (uiop:process-info-pid *cat-proc*)))
           ;; Guard against nil w/h from backend-size
           (setq w (or (and (numberp w) (> w 0) w) 80)
                 h (or (and (numberp h) (> h 0) h) 24))
@@ -990,7 +995,7 @@ Event handlers + daemon I/O + main loop.
                ;; Keyboard reader: block on cat pipe with 0.1s timeout.
                (handler-case
                    (sb-ext:with-timeout 0.1
-                     (let ((raw-ch (read-char tty-in nil nil)))
+                     (let ((raw-ch (read-char *tty-in* nil nil)))
                        (when raw-ch
                          (let ((code (char-code raw-ch)))
                            (queue-event
@@ -1064,12 +1069,12 @@ Event handlers + daemon I/O + main loop.
                                                     (cond (cat (theme-color :dim))
                                                           (sel-p (theme-color :accent))
                                                           (t (theme-color :agent-fg)))
-                                                   nil :bold sel-p)
-                            (incf y-off)))))))
+                                                    nil :bold sel-p)
+                           (incf y-off)))))))
                (sleep 0.1))
-            (uiop:terminate-process cat-proc))
-            (add-msg :system (format nil "* cat ~a ended *" (uiop:process-info-pid cat-proc))))
-          (progn (disconnect-daemon))))
+             (uiop:terminate-process *cat-proc*))
+            (add-msg :system (format nil "* cat ~a ended *" (uiop:process-info-pid *cat-proc*))))
+          (progn (disconnect-daemon)))
 #+END_SRC
 
 * Test Suite