./bootstrap.sh fails on cygwin and mingw

As suggested in
http://old.nabble.com/Note-for-building-gd-wiwith-libpng-1.4-td27808790.html

I have tried to build the recent gd-library.
But I cannot get successful results in ./bootstrap.sh

MinGW+Msys
aclocal (GNU automake) 1.11
autoconf (GNU Autoconf) 2.63
autoheader (GNU Autoconf) 2.63
automake (GNU automake) 1.11
$ ./bootstrap.sh
configure.ac:64: warning: macro {{AM_ICONV' not found in library Makefile.am:18: Libtool library used but}}LIBTOOL' is undefined
Makefile.am:18: The usual way to define {{LIBTOOL' is to add}}AC_PROG_LIBTOOL'
Makefile.am:18: to {{configure.ac' and run}}aclocal' and {{autoconf' again. Makefile.am:18: If}}AC_PROG_LIBTOOL' is in `configure.ac', make sure
Makefile.am:18: its definition is in aclocal's search path.
Failed

Cygwin
aclocal (GNU automake) 1.11.1
autoconf (GNU Autoconf) 2.65
autoheader (GNU Autoconf) 2.65
automake (GNU automake) 1.11.1

$ ./bootstrap.sh
configure.ac:64: warning: macro `AM_ICONV' not found in library
configure.ac:64: error: possibly undefined macro: AM_ICONV
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.

What's wrong with me ?