LDAP authentication started giving:

(9)Bad file descriptor: Could not open password file: (null)

This is because apache 2.2 needs to be told what provider.

Add:

AuthBasicProvider ldap

In addition - to be allowed to use require valid-user add:

AuthzLDAPAuthoritative off

So - in full - the old config:

<Location /location>
  AuthName "Auth NAme"
  AuthType Basic
  AuthLDAPURL ldap://host:port/basedn?attribute
  require valid-user
</Location>

changes to

<Location /location>
  AuthName "Auth NAme"
  AuthType Basic
  AuthBasicProvider ldap
  AuthzLDAPAuthoritative off
  AuthLDAPURL ldap://host:port/basedn?attribute
  require valid-user
</Location>