Example file 'compilation.txt' claims it is supported to mark only the
last message as the error, skipping all 'included from...' lines,
which are often not interesting.  However, instead it marks all lines
except the first as errors.

To reproduce:

    M-x customize-variable
    compilation-error-regexp-alist

and follow the 'see also example file' link.

Screenshot of what I see is attached.

GNU Emacs 24.0.50.1 (i686-pc-linux-gnu, GTK+ Version 2.20.1) of 2010-09-02 on gonzo

Paul