Subject: bug#79308: 30.2; Maximum buffer size exceeded when running package-list-packages

From: Enrico Rivarola <[email-masked]>
Date: Mon, 25 Aug 2025 11:40:24 +0200

Hi,
after upgrading to Emacs 30.2 I've this error message when running the 'package-list-packages' 
command:

"find-file-noselect-1: Maximum buffer size exceeded"

Running the command more times seems to make the message disappear, but doing some tests I found 
that the cause of the problem, at least in my system, seems to be the configuration of 
"custom-file' to 'null-device'.
Leaving it at its default value or setting it to a different real file (e.g. 'my-custom.el' in 
'user-emacs-directory') does not cause any errors.

If it matters my Emacs is a locally 'self compiled' version running on KDE Plasma (Wayland)

In GNU Emacs 30.2 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.43,
  cairo version 1.18.0) of 2025-08-16 built on localhost
System Description: openSUSE Leap 15.6

Configured using:
  'configure --with-libsystemd --with-pop=yes --without-dbus
  --without-gconf --without-gsettings --with-mailutils
  --without-native-compilation --with-json --with-tree-sitter
  --prefix=/home/user/bin/pkg/emacs --with-pgtk --without-xwidgets
  --without-xaw3d --with-gif --with-jpeg --with-png --with-rsvg
  --with-tiff --with-xft --with-xpm --with-gpm=no --with-modules
  --without-pop'

Configured features:
ACL CAIRO FREETYPE GIF GLIB GMP GNUTLS HARFBUZZ JPEG LCMS2 LIBOTF
LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PGTK PNG
RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER
WEBP XIM GTK3 ZLIB

Important settings:
   value of $LANG: it_IT.utf8
   locale-coding-system: utf-8-unix