Hi, upgrading to gcc-4.3.4 (amd64) has gone mostly smoothly, but it's 
broken my util-vserver package and now it segfaults every time I try and 
start a vserver... :-(

...Actually in the course of writing this email I appear to have found a 
solution.  Posting this in case it helps someone else:

It appears that currently stable versions of dietlibc need to be 
compiled with a vanilla compiler under 3.4.6 or they will segfault when 
using a recent util-vserver.  However, I couldn't find a working compile 
under gcc-4.3 for the currently stable dietlibc

However, the following packages at least are fine and dandy after being 
compiled with the new gcc-4.3.4 "hardened" (ie no SSP)
 
    dev-libs/dietlibc-0.33_pre20090721
    sys-cluster/util-vserver-0.30.216_pre2849

My guess is that the earlier dietlibc is/was actually broken in some 
subtle way, but at least this newer version seems "good enough"...

Hope this helps someone

Ed W