This approach will break the development cycle. Since it would not copy things to build/ when items change. I would much rather see we explicitly move things to build/.

noted...

alternatively bring the copy changes into the deployment script?

- name: Building nixos.org
  run: |
    nix build
    mkdir build
    cp -RL ./result/* ./build/
- name: Deploy to Netlify

to something like this...

- name: Building nixos.org
  run: |
    nix build
   	fd -I -t d -x mkdir -p build/{}   
fd -I -t f -t l '(.*?)\.(gpg|svg|xml|ico|css|jpg|gif|doc|pdf|html|png|js|cast|ico|robots.txt)$$' -x 
   cp -a ./result/*{} ./build/{}
- name: Deploy to Netlify

but the cleanest way to rewrite the make file.

With the last proposed solution we would only catch problems once we deploy to Netlify and we wouldn't be able to catch them locally.

I still believe best approach would be to prepend build/ to targets in Makefile.