Add actionable CLI startup diagnostics

ai-code-backends-infra-ghostel.el

@@ -12,6 +12,7 @@
 (require 'ai-code-editor-viewport)
 (require 'ai-code-ghostel-image-preview)
 (require 'ai-code-session-link)
+(require 'ai-code-startup-diagnostics)
 
 ;; Prefer `ghostel-exec' for Ghostel backend startup when available, as
 ;; it simplifies process startup integration.
@@ -879,6 +880,34 @@ ORIG-FILTER is Ghostel's original process filter."
         (ai-code-backends-infra-ghostel--render-output
          buffer orig-filter process output)))))
 
+(defun ai-code-backends-infra-ghostel--capture-native-child-exit-status
+    (process output)
+  "Record a native Ghostel child exit status from PROCESS OUTPUT."
+  (when (and (processp process) (stringp output))
+    (let* ((fragment
+            (or (process-get
+                 process 'ai-code-backends-infra-ghostel--event-fragment)
+                ""))
+           (input (concat fragment output))
+           (input-length (length input))
+           (offset 0)
+           pending)
+      (while (< offset input-length)
+        (let ((parsed
+               (condition-case nil
+                   (read-from-string input offset)
+                 (end-of-file nil))))
+          (if parsed
+              (progn
+                (when (numberp (car parsed))
+                  (ai-code-startup-diagnostics-record-child-exit-status
+                   process (car parsed)))
+                (setq offset (cdr parsed)))
+            (setq pending (substring input offset)
+                  offset input-length))))
+      (process-put
+       process 'ai-code-backends-infra-ghostel--event-fragment pending))))
+
 (defun ai-code-backends-infra-ghostel--wrap-process-filter
     (buffer process)
   "Wrap PROCESS output for the AI Code Ghostel session in BUFFER."
@@ -896,6 +925,9 @@ ORIG-FILTER is Ghostel's original process filter."
       (set-process-filter
        process
        (lambda (proc output)
+         (when (eq orig-filter 'ghostel--events-filter)
+           (ai-code-backends-infra-ghostel--capture-native-child-exit-status
+            proc output))
          (let ((target (or (ignore-errors (process-buffer proc))
                            buffer)))
            (when (buffer-live-p target)

ai-code-backends-infra.el

@@ -21,6 +21,7 @@
 (require 'ai-code-editor-viewport)
 (require 'ai-code-session)
 (require 'ai-code-session-link)
+(require 'ai-code-startup-diagnostics)
 ;; Terminal-specific implementations live in dedicated modules so this
 ;; file can stay focused on shared session orchestration.
 (require 'ai-code-backends-infra-vterm)
@@ -1141,7 +1142,7 @@ were non-nil and append that UUID to the default CLI args."
                found-resume-switch
                (ai-code-backends-infra--selected-session-id)))
          (prompt-p (or arg selected-session-id))
-         (default-args (mapconcat #'identity
+         (default-args (mapconcat #'shell-quote-argument
                                    (append switches
                                            (and selected-session-id
                                                 (list selected-session-id)))
@@ -1152,8 +1153,11 @@ were non-nil and append that UUID to the default CLI args."
          (resolved-args (if prompt-p
                             (split-string-shell-command prompt-args)
                           switches))
-         (command (mapconcat #'identity
-                             (cons program resolved-args)
+         (resolved-program (if (string-prefix-p "~" program)
+                               (expand-file-name program)
+                             program))
+         (command (mapconcat #'shell-quote-argument
+                             (cons resolved-program resolved-args)
                              " ")))
     (list :command command :args resolved-args)))
 
@@ -1311,14 +1315,19 @@ behavior."
    buffer working-dir prefix task-file)
   (ai-code-backends-infra--display-buffer-in-side-window buffer))
 
-(defun ai-code-backends-infra--handle-session-start-failure (buffer session-key process-table)
-  "Handle startup failure for BUFFER and SESSION-KEY in PROCESS-TABLE."
-  (remhash session-key process-table)
-  (if (buffer-live-p buffer)
-      (progn
-        (pop-to-buffer buffer)
-        (message "CLI failed to start - see buffer for error details"))
-    (message "CLI failed to start - process exited immediately")))
+(defun ai-code-backends-infra--handle-session-start-failure
+    (buffer session-key process-table prefix command)
+  "Handle startup failure for BUFFER and SESSION-KEY in PROCESS-TABLE.
+PREFIX identifies the backend that attempted to start.
+COMMAND is the launch command supplied to the terminal backend."
+  (let ((process (gethash session-key process-table))
+        (backend (or prefix
+                     (when (buffer-live-p buffer)
+                       (with-current-buffer buffer
+                         ai-code-backends-infra--session-prefix)))))
+    (remhash session-key process-table)
+    (ai-code-startup-diagnostics-report
+     buffer process backend command)))
 
 (defun ai-code-backends-infra--start-cli-session (options arg)
   "Start a generic CLI session described by OPTIONS and prefix ARG.
@@ -1474,36 +1483,60 @@ TASK-FILE and SOURCE-BUFFER preserve file-to-session binding."
           (if (file-remote-p working-dir)
               env-vars
             (ai-code-editor-viewport-environment env-vars)))
-         (buffer-and-process
-          (ai-code-backends-infra--create-terminal-session
-           resolved-buffer-name working-dir command editor-environment))
-         (new-buffer (car buffer-and-process))
-         (process (cdr buffer-and-process)))
-    (puthash session-key process process-table)
-    ;; Wait for initialization before checking process status
-    (sleep-for ai-code-backends-infra-terminal-initialization-delay)
-    ;; Check if process is still alive after initialization delay
-    (if (and process (process-live-p process))
-        (progn
-          (ai-code-backends-infra--finalize-started-session
-           new-buffer
-           process
-           working-dir
-           resolved-buffer-name
-           process-table
-           resolved-instance
-           prefix
-           escape-fn
-           cleanup-fn
-           multiline-input-sequence
-           post-start-fn
-           task-file)
-          (ai-code-backends-infra--remember-file-session-buffer
-           prefix source-buffer new-buffer))
-      (ai-code-backends-infra--handle-session-start-failure
-       new-buffer
-       session-key
-       process-table))))
+         buffer-and-process
+         startup-failed)
+    (condition-case err
+        (setq buffer-and-process
+              (ai-code-backends-infra--create-terminal-session
+               resolved-buffer-name working-dir command editor-environment))
+      (error
+       (unwind-protect
+           (let ((failure-buffer (get-buffer resolved-buffer-name)))
+             (if failure-buffer
+                 (progn
+                   (ai-code-backends-infra--handle-session-start-failure
+                    failure-buffer
+                    session-key
+                    process-table
+                    prefix
+                    command)
+                   (setq startup-failed t))
+               (signal (car err) (cdr err))))
+         (when cleanup-fn
+           (funcall cleanup-fn)))))
+    (unless startup-failed
+      (let ((new-buffer (car buffer-and-process))
+            (process (cdr buffer-and-process)))
+        (puthash session-key process process-table)
+        ;; Wait for initialization before checking process status
+        (sleep-for ai-code-backends-infra-terminal-initialization-delay)
+        ;; Check if process is still alive after initialization delay
+        (if (and process (process-live-p process))
+            (progn
+              (ai-code-backends-infra--finalize-started-session
+               new-buffer
+               process
+               working-dir
+               resolved-buffer-name
+               process-table
+               resolved-instance
+               prefix
+               escape-fn
+               cleanup-fn
+               multiline-input-sequence
+               post-start-fn
+               task-file)
+              (ai-code-backends-infra--remember-file-session-buffer
+               prefix source-buffer new-buffer))
+          (unwind-protect
+              (ai-code-backends-infra--handle-session-start-failure
+               new-buffer
+               session-key
+               process-table
+               prefix
+               command)
+            (when cleanup-fn
+              (funcall cleanup-fn))))))))
 
 (defun ai-code-backends-infra--toggle-or-create-session (working-dir buffer-name process-table command
                                                                      &optional escape-fn cleanup-fn