hi, There is no glibc be used in cygwin . It use the libiconv. In the iconv.h , the symbol iconv_open is a macro definition. The real function is libiconv_open. I think diff --git a/configure.ac b/configure.ac index 302d74d..3e0b9e6 100644 --- a/configure.ac +++ b/configure.ac @@ -20,6 +20,7 @@ AC_PROG_LIBTOOL # Replace `main' with a function in -lfl: AC_CHECK_LIB(fl, main) AC_CHECK_LIB(iconv, iconv_open) +AC_CHECK_LIB(iconv, libiconv_open) # Checks for header files.