emacs: disable dbus and gvfs backends

dotfiles/emacs.d/README.org

@@ -3649,9 +3649,8 @@ I don't use iedit directly, but it is used by [[*emr][emr]] and I need to disabl
   :ensure nil
   :commands tramp
   :init
-  ;; Avoid TRAMP's GVFS backend on sessions where org.gtk.vfs.Daemon is not
+  ;; Avoid TRAMP's GVFS backend entirely.  It depends on D-Bus/GVFS desktop
-  ;; activatable.  Buffer/recent-file completion can otherwise trigger noisy
+  ;; services, while this config uses ordinary TRAMP methods.
-  ;; DBus ServiceUnknown errors while inspecting TRAMP candidates.
   (setq tramp-gvfs-methods nil)
   :config
   (setq tramp-default-method "scp")
@@ -3668,12 +3667,9 @@ I don't use iedit directly, but it is used by [[*emr][emr]] and I need to disabl
 #+END_SRC
 ** dbus
 #+BEGIN_SRC emacs-lisp
-(with-eval-after-load 'dbus
+;; D-Bus is disabled by lisp/dbus.el, which shadows Emacs' built-in dbus.el.
-  ;; This hook reports even handled DBus errors in the echo area.  That is
+;; Keep the event hook empty in case another environment loads the real library.
-  ;; usually noise in this config, especially during completion paths which may
+(setq dbus-event-error-functions nil)
-  ;; probe optional desktop services.
-  (remove-hook 'dbus-event-error-functions
-               #'dbus-notice-synchronous-call-errors))
 #+END_SRC
 ** narrow-indirect
 #+BEGIN_SRC emacs-lisp

dotfiles/emacs.d/init.el

@@ -10,6 +10,15 @@
 (defun emacs-directory-filepath (filename)
   (expand-file-name filename user-emacs-directory))
 
+(add-to-list 'load-path (emacs-directory-filepath "lisp"))
+
+;; Treat this Emacs as if it was built without D-Bus.  The local
+;; lisp/dbus.el shim prevents `require' from loading the built-in dbus.el,
+;; whose top-level form eagerly opens system and session bus connections.
+(setq features (delq 'dbusbind features))
+(setq dbus-compiled-version nil
+      dbus-runtime-version nil)
+
 (load-file (expand-file-name "elpaca-installer.el" user-emacs-directory))
 
 ;; Elpaca's initial queue logger can fire during self-bootstrap before its

dotfiles/emacs.d/lisp/dbus.el

@@ -0,0 +1,93 @@
+;;; dbus.el --- Disabled D-Bus shim -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; This file intentionally shadows Emacs' built-in net/dbus.el.  Loading the
+;; built-in library initializes D-Bus connections at top level, which is noisy
+;; and fragile in this configuration.
+
+;;; Code:
+
+(setq features (delq 'dbusbind features))
+(setq dbus-compiled-version nil
+      dbus-runtime-version nil)
+
+(unless (boundp 'dbus-error)
+  (define-error 'dbus-error "D-Bus disabled in this Emacs config"))
+
+(defvar dbus-debug nil)
+(defvar dbus-event-error-functions nil)
+(defvar dbus-registered-objects-table (make-hash-table :test #'equal))
+
+(defconst dbus-service-dbus "org.freedesktop.DBus")
+(defconst dbus-path-dbus "/org/freedesktop/DBus")
+(defconst dbus-path-local "/org/freedesktop/DBus/Local")
+(defconst dbus-interface-dbus "org.freedesktop.DBus")
+(defconst dbus-interface-peer "org.freedesktop.DBus.Peer")
+(defconst dbus-interface-introspectable "org.freedesktop.DBus.Introspectable")
+(defconst dbus-interface-properties "org.freedesktop.DBus.Properties")
+(defconst dbus-interface-objectmanager "org.freedesktop.DBus.ObjectManager")
+(defconst dbus-interface-monitoring "org.freedesktop.DBus.Monitoring")
+(defconst dbus-interface-local "org.freedesktop.DBus.Local")
+(defconst dbus-service-emacs "org.gnu.Emacs")
+(defconst dbus-path-emacs "/org/gnu/Emacs")
+(defconst dbus-interface-emacs "org.gnu.Emacs")
+
+(defconst dbus-error-dbus "org.freedesktop.DBus.Error")
+(defconst dbus-error-failed "org.freedesktop.DBus.Error.Failed")
+(defconst dbus-error-service-unknown "org.freedesktop.DBus.Error.ServiceUnknown")
+
+(defmacro dbus-ignore-errors (&rest body)
+  "Execute BODY, suppressing `dbus-error' unless `dbus-debug' is non-nil."
+  (declare (indent 0) (debug t))
+  `(condition-case err
+       (progn ,@body)
+     (dbus-error (when dbus-debug (signal (car err) (cdr err))))))
+
+(defun imalison:dbus-disabled (&rest _args)
+  "Signal that D-Bus is intentionally unavailable in this config."
+  (signal 'dbus-error '("D-Bus disabled in this Emacs config")))
+
+(dolist (function
+         '(dbus-call-method
+           dbus-call-method-asynchronously
+           dbus-send-signal
+           dbus-method-return-internal
+           dbus-method-error-internal
+           dbus-register-service
+           dbus-unregister-service
+           dbus-register-signal
+           dbus-register-method
+           dbus-unregister-object
+           dbus-register-property
+           dbus-register-monitor
+           dbus-init-bus
+           dbus-ping
+           dbus-introspect
+           dbus-introspect-xml
+           dbus-get-property
+           dbus-set-property
+           dbus-get-all-properties
+           dbus-get-all-managed-objects))
+  (defalias function #'imalison:dbus-disabled))
+
+(defun dbus-list-activatable-names (&optional _bus) nil)
+(defun dbus-list-names (&optional _bus) nil)
+(defun dbus-list-known-names (&optional _bus) nil)
+(defun dbus-list-queued-owners (&rest _args) nil)
+(defun dbus-get-name-owner (&rest _args) nil)
+(defun dbus-list-hash-table () nil)
+
+(defun dbus-event-bus-name (_event) nil)
+(defun dbus-event-message-type (_event) nil)
+(defun dbus-event-serial-number (_event) nil)
+(defun dbus-event-service-name (_event) nil)
+(defun dbus-event-destination-name (_event) nil)
+(defun dbus-event-path-name (_event) nil)
+(defun dbus-event-interface-name (_event) nil)
+(defun dbus-event-member-name (_event) nil)
+(defun dbus-event-handler (_event) nil)
+(defun dbus-event-arguments (_event) nil)
+
+(provide 'dbus)
+
+;;; dbus.el ends here

dotfiles/emacs.d/lisp/tramp-gvfs.el

@@ -0,0 +1,41 @@
+;;; tramp-gvfs.el --- Disabled TRAMP GVFS backend -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; This file intentionally shadows Emacs' built-in net/tramp-gvfs.el.  The real
+;; backend depends on D-Bus and GVFS desktop services; this config uses ordinary
+;; TRAMP methods instead.
+
+;;; Code:
+
+(require 'tramp)
+
+(defconst tramp-gvfs-enabled nil
+  "Non-nil when the disabled GVFS backend is available.")
+
+(defvar tramp-gvfs-methods nil
+  "Disabled list of TRAMP methods handled through GVFS.")
+(setq tramp-gvfs-methods nil)
+
+(defconst tramp-goa-methods nil
+  "Disabled list of GNOME Online Accounts TRAMP methods.")
+
+(defvar tramp-media-methods nil
+  "Disabled list of media-device TRAMP methods.")
+(setq tramp-media-methods nil)
+
+(defvar tramp-gvfs-file-name-handler-alist nil
+  "Disabled GVFS file name handler alist.")
+
+(defun tramp-gvfs-file-name-p (_filename)
+  "Return nil because the GVFS backend is disabled."
+  nil)
+
+(defun tramp-gvfs-file-name-handler (operation &rest args)
+  "Signal an unsupported OPERATION for the disabled GVFS backend."
+  (signal 'file-error
+          (list "TRAMP GVFS backend disabled in this Emacs config"
+                operation args)))
+
+(provide 'tramp-gvfs)
+
+;;; tramp-gvfs.el ends here