--text follows this line-- When using emacs with X, it crashes when it should display the utf8 char: ∗ In terminal mode, no crash appears. Just generate a file with this utf8 char in it and make emacs display it in the normal view. As long as the char is not visible, the emacs is fine. Please generate your own debugging log. The debian version seems not to contain any useful debug symbols... --- hexdump crash.txt 0000000 88e2 0a97 0000004 --- In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.30, cairo version 1.16.0)  of 2022-01-24, modified by Debian built on lgw01-amd64-048 System Description: Ubuntu 22.04.1 LTS Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Mark set Making completion list... Configured using:  'configure --build x86_64-linux-gnu --prefix=/usr  --sharedstatedir=/var/lib --libexecdir=/usr/lib  --localstatedir=/var/lib --infodir=/usr/share/info  --mandir=/usr/share/man --enable-libsystemd --with-pop=yes  --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/27.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/27.1/site-lisp:/usr/share/emacs/site-lisp  --with-sound=alsa --without-gconf --with-mailutils --build  x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib  --libexecdir=/usr/lib --localstatedir=/var/lib  --infodir=/usr/share/info --mandir=/usr/share/man --enable-libsystemd  --with-pop=yes  --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/27.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/27.1/site-lisp:/usr/share/emacs/site-lisp  --with-sound=alsa --without-gconf --with-mailutils --with-cairo  --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars  'CFLAGS=-g -O2  -ffile-prefix-map=/build/emacs-NbbgEv/emacs-27.1+1=. -fstack-protector-strong  -Wformat -Werror=format-security -Wall' 'CPPFLAGS=-Wdate-time  -D_FORTIFY_SOURCE=2' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro'' Configured features: XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD JSON PDUMPER LCMS2 GMP Important settings:   value of $LC_MONETARY: de_DE.UTF-8   value of $LC_NUMERIC: de_DE.UTF-8   value of $LC_TIME: de_DE.UTF-8   value of $LANG: en_US.UTF-8   value of $XMODIFIERS: @im=ibus   locale-coding-system: utf-8-unix Major mode: Text Minor modes in effect:   tooltip-mode: t   global-eldoc-mode: t   electric-indent-mode: t   mouse-wheel-mode: t   tool-bar-mode: t   menu-bar-mode: t   file-name-shadow-mode: t   global-font-lock-mode: t   font-lock-mode: t   auto-composition-mode: t   auto-encryption-mode: t   auto-compression-mode: t   line-number-mode: t   transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg epg-config gnus-util rmail rmail-loaddefs text-property-search time-date subr-x seq mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils term/xterm xterm byte-opt gv bytecomp byte-compile cconv tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads dbusbind inotify lcms2 dynamic-setting system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs) Memory information: ((conses 16 49893 8601)  (symbols 48 6119 1)  (strings 32 15732 2062)  (string-bytes 1 504569)  (vectors 16 8080)  (vector-slots 8 83300 7198)  (floats 8 23 356)  (intervals 56 250 0)  (buffers 1000 13))