lftp compile problem

[Steve Coates]

I am trying to build lftp 3.0.7. The configure works fine but when I compile I get the following. Any ideas?

No suffix list.
Making all in include
No suffix list.
make all-am
No suffix list.
Making all in readline-4.3
rm -f vi_mode.o
gcc -c -DHAVE_CONFIG_H -I. -I. -I/usr/local/include -DRL_LIBRARY_VERSION='"4.3"' -g -O vi_mode.c
vi_mode.c: In function `_rl_vi_change_mbchar_case':
vi_mode.c:691: error: `mbrtowc' undeclared (first use in this function)
vi_mode.c:691: error: (Each undeclared identifier is reported only once
vi_mode.c:691: error: for each function it appears in.)
*** Error exit code 1

Stop.
*** Error exit code 1

Stop.