configure --with-readline produces:
gcc -g -O2
-DSQSH_RC='"/usr/local/etc/sqshrc:${HOME}/.sqshrc"'
-DUSE_READLINE -DOLD_READLINE
-I/cygdrive/c/sybase15/OCS-15_0/include -c -o
sqsh_readline.o sqsh_readline.c
sqsh_readline.c: In function `sqsh_readline_init':
sqsh_readline.c:131: warning: assignment from
incompatible pointer type
The configure script believes that this is the old
readline for some reason and defines OLD_READLINE.
My solution was to download and compile libreadline-5.0
(I'm sure 4.0 will work too). Then the configure script
finds rl__completion_matches in libreadline.a . Of
course if one installs readline in its default
installation directory /usr/local/... then one must
specify INCDIRS and LIBDIRS before running configure.