Bug#915261: SysV init regression thanks to broken "container detection" logic

[GSR]

Package: udev
Version: 239-14
Followup-For: Bug #915261
Severity: serious

Severity should be at least serious, for two reasons. First so it gets
listed with apt-listbugs default levels and people can decide what to
do. And second, it does not affect every user, but those affected have
to handle a broken boot, which is not nice.

Per https://release.debian.org/testing/rc_policy.txt it is release
critical.
---8<---
* makes unrelated software on the system (or the whole system)
  break
--->8---

GSR