cp: cannnot stat 'modules/*': No such file or directory

[Deleted user]

I learnt to wrote a sample extension. I found nothing wrong before making install.
Installing shared extensions: /usr/share/php/lib/php/extensions/debug-non-zts-20151012/ cp: cannot stat 'modules/*': No such file or directory make: *** [install-modules] Error 1
I checked that there's a lot of files built after these steps. And I found nothing inside the modules directory, no .so file is inside.

Of course, I make clean it and then re-install it once again. But it's still the same. I have no idea what's wrong with it after googling.

So could you help me?