mingw/mingw-packages/mingw-w64-bullet/bullet-x86_64.install

post_install() {
  cd mingw64
  local _prefix=$(pwd -W)
  cd -
  for f in mingw64/lib/cmake/bullet/*.cmake; do
    sed -e "s|/mingw64|${_prefix}|g" -i ${f}
  done
}

post_upgrade() {
  post_install
}