should be on MacOS X

I decided to build 7.3.1 on MacOS 10.2.3 with PAM support.

    % ./configure --with-pam --with-openssl
    ...
    configure: error: header file <security/pam_appl.h> is required for PAM

There is, however, a /usr/include/pam/pam_appl.h.  So,  I did a
search/replace in configure and replaced it.

    % make
    ...
    gcc -traditional-cpp -g -O2 -Wall -Wmissing-prototypes
-Wmissing-declarations -I../../../src/include   -c -o auth.o auth.c
    auth.c:45:31: security/pam_appl.h: No such file or directory
    ...
    make[3]: *** [auth.o] Error 1

So in auth.c,  I did the same find/replace:

    #ifdef USE_PAM
    #include <pam/pam_appl.h>

I added a file to /etc/pam.d for postgresql:

    % cat /etc/pam.d/postgresql
    auth       required       pam_nologin.so
    auth       sufficient     pam_securityserver.so
    auth       sufficient     pam_unix.so
    auth       required       pam_deny.so
    account    required       pam_permit.so
    password   required       pam_deny.so
    session    required       pam_uwtmp.so

And then it just worked:  my user login for the machine got me into
psql.

- Aaron