Hi, I tried to compile CLN with MinGW 64-bit (compilation for 32bit works fine). Downloaded mingw-w64-1.0-bin_i686-linux_20110117.tar.bz2 from sourceforge and installed it. git clone git://www.ginac.de/cln.git cd cln autoreconf -i ./configure --host=x86_64-w64-mingw32 --prefix=/usr/x86_64-w64-mingw32 --without-gmp make and this is the result (complete output): Making all in src make[1]: Entering directory `/home/jan/mingw/cln/src' /bin/bash ../libtool --tag=CXX --mode=compile x86_64-w64-mingw32-g++ -DHAVE_CONFIG_H -I. -I../autoconf -I../include -I../src -I../include -I../src -g -O2 -MT cl_alloca.lo -MD -MP -MF .deps/cl_alloca.Tpo -c -o cl_alloca.lo `test -f 'base/cl_alloca.cc' || echo './'`base/cl_alloca.cc libtool: compile: x86_64-w64-mingw32-g++ -DHAVE_CONFIG_H -I. -I../autoconf -I../include -I../src -I../include -I../src -g -O2 -MT cl_alloca.lo -MD -MP -MF .deps/cl_alloca.Tpo -c base/cl_alloca.cc -o cl_alloca.o In file included from ./base/cl_sysdep.h:10:0, from base/cl_alloca.cc:4: ../include/cln/intparam.h:26:2: error: #error "Type char * does not fit into a long!!" In file included from ../include/cln/types.h:10:0, from ./base/cl_macros.h:6, from ./base/cl_sysdep.h:56, from base/cl_alloca.cc:4: ../include/cln/intparam.h:26:2: error: #error "Type char * does not fit into a long!!" base/cl_alloca.cc: In function 'cln::cl_alloca_header* cln::cl_alloc_alloca_header(size_t)': base/cl_alloca.cc:20:40: error: cast from 'long int*' to 'long int' loses precision make[1]: *** [cl_alloca.lo] Error 1 make[1]: Leaving directory `/home/jan/mingw/cln/src' make: *** [all-recursive] Error 1 Any ideas? Thanks, Jan