Even though Ethereal doesn't use C++, if the compiler isn't installed, 
configure might issue these messages:
> checking how to run the C++ preprocessor... /lib/cpp
> configure: error: C++ preprocessor "/lib/cpp" fails sanity check
> See `config.log' for more details.
with config.log containing:
> configure:4981: /lib/cpp  conftest.cc
> cpp: installation problem, cannot exec 'cc1plus': No such file or 
directory
This is due to a bug in libtool, fixed in version 1.5.20.  Is there any 
reason not to have autogen.sh check for libtool version >= 1.5.20, as it 
checks now for version >= 1.4?  (Incidentally, configure.in could be 
simplified with version 1.5.20.)
Unfortunately, if someone encounters this problem, it's not sufficient 
to install the latest version of libtool in /usr/local, say, with $PATH 
set appropriately to override the older version in /usr.  Somewhere 
along the line, libtool invokes the aclocal perl script, part of 
Automake, which hardwires the aclocal directory.  E.g., if aclocal is 
installed in /usr/bin, it includes the line:
> $acdir = '/usr/share/aclocal';
which means that /usr/share/aclocal/libtool.m4 is invoked instead of the 
latest version installed in /usr/local/share/aclocal/libtool.m4.
I can't think of a simple way of checking for this dependency problem, 
but I suppose a detailed error message in autogen.sh would be good 
enough; it's not likely that someone would already have a newer version 
of libtool overlaid onto an older version.
Graeme Hewson