Hi!

Highlights in this iteration

   * removed indentation from commit messages
   * replaced and-let* with and=>
   * have added #:phases return #t
   * removed extra cross-gcc mingw configure flags
   * removed custom cross-gcc-mingw install phase
   * use name "libc" instead of "mingw-w64", allowing a clean-up
   * add some comments
   * document gcc-cross-environment-variables.patch harder

Usage
    ./pre-inst-env guix build --target=i686-w64-mingw32 guile

Greetings,
Jan