warning: unable to access '/root/.config/git/config':

sudo でgit を実行するとき下記のようにエラーが出た

# sudo -u user /usr/bin/git pull
warning: unable to access '/root/.config/git/config': ????????
warning: unable to access '/root/.gitconfig': ????????

原因

# sudo -u user /usr/bin/git pull

# sudo -i -u user env
HOME=/home/user

# sudo -u user HOME=/home/user /usr/bin/git pull

対処

参考
https://qiita.com/chroju/items/375582799acd3c5137c7