Cross Compile

On a Linux system you can compile binaries for windows by using a cross compile environment. Here are our notes for setting up a suitable cross compile environment:

sudo apt-get install mingw-w64  win-iconv-mingw-w64-dev libgcrypt-mingw-w64-dev   # on a Ubuntu-based system 

With these installed, on Ubuntu almost everything is available.

Except for gnutls, where the windows binaries need to be downloaded from here:
Unpack the binary zips (e.g. under $HOME/gnutls-win), then add a suitable symlink for the header files which are located under lib/includes, e.g.

cd win32-build
mkdir include
cd include
ln -s ../lib/includes gnutls

both for the win32 and the win64 builds, accordingly. Additionally, the pkg-config file "gnutls.pc" contains the prefix=/usr/local, which is obviously wrong in our case. My suggestion is to edit the file lib/gnutls.pc and adapt the "prefix=..." entry to your actual path where the library was unpacked, i.e. the root path of where lib, bin directory and your hand-created include symlink reside.

For building gwenhywfar, now do the following for a win32 build (which seems to catch mismatching GWENHYWFAR_CB attributes best) and make sure to choose the PKG_CONFIG_PATH according to your local gnutls download:

mkdir build-mingw-w32
cd build-mingw-w32
PATH=/usr/i686-w64-mingw32/bin:$PATH \
 ../configure --host=i686-w64-mingw32 \
 --with-iconv=/usr/i686-w64-mingw32 --with-libgcrypt-prefix=/usr/i686-w64-mingw32 \
 --with-libgpg-error-prefix=/usr/i686-w64-mingw32 \
 --disable-binreloc --with-guis='' \
 --disable-ssl \
 --enable-error-on-warning \

And additionally a 64bit target system can be compiled for, which might catch even further compiler warnings/errors:

mkdir build-mingw-w64
cd build-mingw-w64
PATH=/usr/x86_64-w64-mingw32/bin:$PATH \
 ../configure --host=x86_64-w64-mingw32 \
 --with-iconv=/usr/x86_64-w64-mingw32 --with-libgcrypt-prefix=/usr/x86_64-w64-mingw32 \
 --with-libgpg-error-prefix=/usr/x86_64-w64-mingw32 \
 --disable-binreloc --with-guis='' \
 --disable-ssl \
 --enable-error-on-warning \