If running with (gpm-mouse-mode 1) and if you stop the gpm server, then emacs dies with Fatal error (6)Aborted Output from "bt full" below; xbacktrace printed nothing at all. The backtrace shows it at the abort() under the EBADF case in wait_reading_process_output(). I think when Gpm_GetEvent gets an eof from the server it closes gpm_fd; maybe that's the bad fd in question. In GNU Emacs 23.0.60.1 (i586-pc-linux-gnu, GTK+ Version 2.12.10) of 2008-06-13 on blah.blah configured using `configure 'CFLAGS=-O -g' '--prefix=/down/emacs/b/inst' '--with-x-toolkit=gtk'' Important settings: value of $LC_ALL: nil value of $LC_COLLATE: nil value of $LC_CTYPE: nil value of $LC_MESSAGES: nil value of $LC_MONETARY: nil value of $LC_NUMERIC: nil value of $LC_TIME: nil value of $LANG: en_AU value of $XMODIFIERS: nil locale-coding-system: iso-latin-1-unix default-enable-multibyte-characters: t Major mode: Lisp Interaction Minor modes in effect: gpm-mouse-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t global-auto-composition-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t