I just started using Rome v2.7 and Root v5.14.00. I have run into a rather
interesting issue trying to compile my analyzer. I tracked the problem to the
fact that both Root and Rome are loading their own version of a header file
called TArrayL64.h. The content of the two files are essentially identical. I
solved the problem by changing the conditional at the start of the file
$ROMESYS/include/TArrayL64.h from

#ifndef TArrayL64_H
#define TArrayL64_H

to

#ifndef ROOT_TArrayL64
#define ROOT_TArrayL64

The latter is what I found in the Root version of the file. Now it only gets
loaded once. I looked at the svn sources that I just updated and it also uses
TArrayL64_H.

Question, why are there two copies.

UPDATE 2-21-07:
It seems that Root was the cause of this. Rome has used this header for some
time, but earlier versions of Root did not include it.