1. Clone wallet sources
git clone https://github.com/nutucoin/nutucoinwallet.git
2. Set symbolic link to coin sources at the same level as src. For example:
ln -s ../nutucoin cryptonote
Alternative way is to create git submodule:
git submodule add https://github.com/nutucoin/nutucoin.git cryptonote
3. Build
mkdir build && cd build && cmake .. && make