It seems "readline" isn't linked in the Mac build and installation. 

Configure or package repository don't indicate any issues, and yet history completions fail on mclient's sql prompt.

Regards,
-m.


$ sudo port list | grep readline
gauche-readline                @0.1            devel/gauche-readline
hs-readline                    @1.0.1.0        devel/hs-readline
pure-readline                  @0.1            devel/pure-readline
readline                       @6.2.000        devel/readline
readline-4                     @4.3            devel/readline-4
readline-5                     @5.2.014        devel/readline-5
...
...


$ more config.log | grep readline
configure:18493: checking readline/readline.h usability
configure:18493: checking readline/readline.h presence
configure:18493: checking for readline/readline.h
configure:18495: checking for readline in -lreadline
configure:18520: gcc -o conftest  -g    conftest.c -lreadline    >&5
configure:18631: checking for rl_completion_matches in -lreadline
configure:18656: gcc -o conftest  -g    conftest.c -lreadline  -lreadline   >&5
| #include <readline/readline.h>
ac_cv_header_readline_readline_h=yes
ac_cv_lib_readline_readline=yes
ac_cv_lib_readline_rl_completion_matches=yes