No subject

ZEBRA_MARC_FORMAT
And ZEBRA_LANGUAGE
All it would have to do is set those parameters or ask for confirmation...
Same could be done with INSTALL_MODE  (dev mode is the most appropriate
in many structures, even for "little libraries" when you want some
support) INSTALL_SRU
AUTH_INDEX_MODE grs1 would be mandatory for UNIMARC installation.

and other environnement variables enclosed in
install_misc/environment_MakeFile.PL could be displayed and asked for
confirmation before getting to the make; make install.
my 2 cents.
-- 
Henri-Damien LAURENT