[Exim] Installing with ${ROOT}

I install using

make install ROOT=tempdest

for later installation at /

Which works great, except that the created etc/aliases file erroneously
contains the tempdest bit in this section:

system_aliases:
...
data = ${lookup{$local_part}lsearch{tempdest/etc/aliases}}
...

Am I right in using ROOT in the role of the usual DESTDIR for exim? In
which case is this behaviour wrong?

This is version 4.12

Andrew Walrond

(Please include my email in any replies)