With foo.el and foo.pl below, running emacs -Q foo.el M-x eval-buffer produces a compilation window showing only "xxx.xx" bits, where I hoped setting compilation-scroll-output to `t' in foo.el would make it follow the further output after that, ie. the "bar" lines (which you can see by switching to the *compilation* buffer and scrolling down). The foo.pl script is merely to print the provoking output. It's a long line arriving as its first 1024 bytes and then enough to just fill the 10-line compilation window. During the second sleep the end of the "xxx.xx" is the last line in the window. I get the problem on both a console tty and under gtk X, and in both the debian packaged 22.2 and my build of the current cvs. It seems to depend on the sleeps, ie. pauses in the output, so if you don't get the effect you might try increasing them a bit. In GNU Emacs 22.2.1 (i486-pc-linux-gnu, GTK+ Version 2.12.9) of 2008-04-27 on raven, modified by Debian configured using `configure '--build=i486-linux-gnu' '--host=i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs22:/etc/emacs:/usr/local/share/emacs/22.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/22.2/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/22.2/leim' '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g' 'CPPFLAGS='' 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 locale-coding-system: iso-8859-1 default-enable-multibyte-characters: t Major mode: Lisp Interaction Minor modes in effect: show-paren-mode: t encoded-kbd-mode: t file-name-shadow-mode: t unify-8859-on-encoding-mode: t utf-translate-cjk-mode: t auto-compression-mode: t line-number-mode: t