How to install Magento 2 with empty database password

The following works for me on Ubuntu:

./bin/magento setup:install \
    --db-host=localhost \
    --db-name=magento \
    --db-user=root \
    --backend-frontname=admin \
    --base-url=http://some.host/ \
    --language=en_US \
    --timezone=America/Chicago \
    --currency=USD \
    --admin-lastname=Admin \
    --admin-firstname=Admin \
    [email protected] \
    --admin-user=admin \
    --admin-password=123123q \
    --cleanup-database \
    --use-rewrites=1

The problem may be that you are using remote MySQL host, not localhost. Not sure that it is possible to connect to remote MySQL host without password.