sysutils/libgtop2 fails to configure; the error apparently refers to a
missing mnttab.h; AFAIK the way to get info about the mounted file systems
is to use getmntinfo, which requires statvfs.h; it seems the package has
not yet been put inline with the statvfs change. This ofcourse stops the
compilation of some parts of Gnome2.6. 

Cheers.