dev-lua/luv unpacks but throws an error says directory ${S} does not exist.

neovim also demands luajit use flags for 3 packages:

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)

1. required by app-editors/neovim-0.9.5::editors-kit
2. required by neovim (argument)
   >=dev-lua/lpeg-1.0.2 luajit
3. required by app-editors/neovim-0.9.5::editors-kit
4. required by neovim (argument)
   >=dev-lua/luv-1.48.0 luajit
5. required by app-editors/neovim-0.9.5::editors-kit
6. required by neovim (argument)
   >=dev-lua/mpack-1.0.4 luajit