cloning git respositories requires user interaction

[Mic92]

The user has to hit enter manually for some commands:

$ nix-shell -p vimPlugins.pluginnames2nix --command "vim-plugin-names-to-nix"
ash: /run/user/1000/env-vars: cannot overwrite existing file
Plugin: vim-pi
Home page: https://bitbucket.org/vimcommunity/vim-pi
Source URL: https://bitbucket.org/vimcommunity/vim-pi (type git)
name: 'vim-pi'
Target: /tmp/vim2nix-joerg/vim-pi
git clone --recursive --depth 1 'https://bitbucket.org/vimcommunity/vim-pi' '/tmp/vim2nix-joerg/vim-pi'
:!git clone --recursive --depth 1 'https://bitbucket.org/vimcommunity/vim-pi' '/tmp/vim2nix-joerg/vim-pi'
                                                                                                         Cloning into '/tmp/vim2nix-joerg/vim-pi'...
remote: Counting objects: 43, done.
remote: Compressing objects: 100% (39/39), done.
remote: Total 43 (delta 1), reused 26 (delta 0)
Unpacking objects: 100% (43/43), done.
Press ENTER or type command to continue

Is using :silent ! the right approach here?