MALLOC_PERTURB_: everyone should set this envvar

[Bill Nottingham]

Jim Meyering (jim at meyering.net) said: 
> I posted about MALLOC_PERTURB_ about a year ago,
> 
>     http://thread.gmane.org/gmane.linux.redhat.fedora.devel/132690
> 
> but it is clear that not everyone is setting the variable, so for those
> who didn't take the time last year, or who are new to the subject,
> do yourself a favor and set MALLOC_PERTURB_ to a value in 1..255
> everywhere.

See the 'debugmode' package.

Bill