Hi Thomas, sorry for BIG BIG delay, gnarwl seem dead and I am undecided if fix the bugs or orphaned the package.
Anyway, phamm-ldap-vacation provide only a schema file /etc/ldap/schema/phamm-vacation.schema compatible with ISPEnv2.schema who removed from gnarwl source due license ambiguity phamm-ldap-vacation require slapd because not have sense install it without a LDAP server could be a good suggestions for gnarwl not Recommends phamm-ldap-vacation but Suggests it, anyway Recommends does not force install package, but using apt-get the final effect is the same Alessandro - Lota