Docker build fails: invalid choice: 1 (choose from 'postgresql', 'sqlite', 'mysql', 'oracle')

[0mars]

using branch master

usage: askbot-setup [-h] [--root-directory ROOT_DIR] [--proj-name PROJ_NAME]
                    [--media-root MEDIA_ROOT] [--static-root STATIC_ROOT]
                    [--force] [--noinput] [--db-settings DATABASE_SETTINGS]
                    [--db-engine {postgresql,sqlite,mysql,oracle}]
                    [--db-name DATABASE_NAME] [--db-user DATABASE_USER]
                    [--db-password DATABASE_PASSWORD]
                    [--db-host DATABASE_HOST] [--db-port DATABASE_PORT]
                    [--admin-name ADMIN_NAME] [--admin-email ADMIN_EMAIL]
                    [--domain-name DOMAIN_NAME]
                    [--language-code LANGUAGE_CODE] [--timezone TIMEZONE]
                    [--log-file-path LOG_FILE_PATH]
                    [--email-settings EMAIL_SETTINGS]
                    [--server-email SERVER_EMAIL]
                    [--default-from-email DEFAULT_FROM_EMAIL]
                    [--email-host-user EMAIL_HOST_USER]
                    [--email-host-password EMAIL_HOST_PASSWORD]
                    [--email-subject-prefix EMAIL_SUBJECT_PREFIX]
                    [--email-host EMAIL_HOST] [--email-port EMAIL_PORT]
                    [--email-use-tls] [--email-backend EMAIL_BACKEND]
                    [--admin-settings ADMIN_SETTINGS]
                    [--language-settings LANGUAGE_SETTINGS]
                    [--logging-settings LOGGING_SETTINGS]
                    [--caching-settings CACHING_SETTINGS]
                    [--append-settings EXTRA_SETTINGS]
askbot-setup: error: argument --db-engine/-e: invalid choice: 1 (choose from 'postgresql', 'sqlite', 'mysql', 'oracle')

when replacing with postgresql as a string command becomes

RUN cd /src/ && python setup.py install \
    && askbot-setup -n /${SITE} -e postgresql -d postgres -u postgres -p askbotPW --db-host=postgres --db-port=5432 --logfile-name=stdout --no-secret-key --create-project container-uwsgi

and the output error is

askbot-setup: error: argument --db-engine/-e: invalid int value: 'postgresql'

[rs2]

Xref #891