There are currently no open bugs.

"upgrade-system" versions published in Ubuntu

Cosmic (1.7.3.1): universe/admin
Bionic (1.7.3.0): universe/admin
Xenial (1.7.3.0): universe/admin
Trusty (1.6.3.4): universe/admin
Precise-updates (1.6.1.0+precise1): universe/admin
Precise (1.6.1.0): universe/admin