Source: upstart Source-Version: 1.11-5 The upstart package seems both unmaintained in Debian[1] and upstream. It also has open RC bugs and was removed from stretch five months ago. I therefore suggest to remove the package.
If there are no objections, I'll reassign this bug report to ftp.d.o in a week or so. Ansgar [1] The current version in Debian is 1.11 which was released in 2013. There have been 5 upstream releases since then, the last in 2014.