bauble does not start; no sqlalchemy and/or wrong version

[A]

Description: Ubuntu 16.04.6 LTS
Release: 16.04

bauble:
  Installed: 0.9.7-2.1
  Candidate: 0.9.7-2.1

sqlalchemy was not installed, so I installed the following:

# apt-cache policy python3-sqlalchemy
python3-sqlalchemy:
  Installed: 1.0.11+ds1-1ubuntu2
  Candidate: 1.0.11+ds1-1ubuntu2
  Version table:
 *** 1.0.11+ds1-1ubuntu2 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu xenial/main i386 Packages
        100 /var/lib/dpkg/status

After installing now (from the command line) I get:

$ bauble
Traceback (most recent call last):
  File "/usr/bin/bauble", line 23, in <module>
    bauble.main()
  File "/usr/share/bauble/__init__.py", line 175, in main
    import bauble.pluginmgr as pluginmgr
  File "/usr/share/bauble/pluginmgr.py", line 31, in <module>
    import bauble.db as db
  File "/usr/share/bauble/db.py", line 18, in <module>
    raise error.SQLAlchemyVersionError(msg)
bauble.error.SQLAlchemyVersionError: SQLAlchemyVersionError: This version of Bauble requires SQLAlchemy 0.5.0 or greater.Please download and install a newer version of SQLAlchemy from http://www.sqlalchemy.org or contact your system administrator.