chrony tests fail with new glibc 2.31

Note: bug 1863590 is resolved

Also fails the syscall filtering, working with the Debian maintainer to get this right.

Note: there might be more SW out there who has impact by:
- prototype of gettimeofday() changed (hits us as FTFBS)
- The adjtimex() function in glibc was switched to the clock_adjtime system call (hit us in filtering)

The new version isn't in Debian yet to sync it, but give it a few days ...

The MP at https://code.launchpad.net/~paelzer/ubuntu/+source/chrony/+git/chrony/+merge/380463 has the merge of the new version; seems to work fine in tests.

We built it yesterday in proposed PPAs and it worked.
But now FTFBS on some archietctures - new bug 1867316

This bug was fixed in the package chrony - 3.5-6ubuntu1

---------------
chrony (3.5-6ubuntu1) focal; urgency=medium

  * Merge with Debian unstable (LP: #1866753). Remaining changes:
    - d/chrony.conf: use ubuntu ntp pool and server (LP 1744664 1754358)
    - Set -x as default if unable to set time (e.g. in containers) (LP 1589780)
      Chrony is a single service which acts as both NTP client (i.e. syncing the
      local clock) and NTP server (i.e. providing NTP services to the network),
      and that is both desired and expected in the vast majority of cases.
      But in containers syncing the local clock is usually impossible, but this
      shall not break the providing of NTP services to the network.
      To some extent this makes chrony's default config more similar to 'ntpd',
      which complained in syslog but still provided NTP server service in those
      cases.
      + debian/chrony.service: allow the service to run without CAP_SYS_TIME
      + debian/control: add new dependency libcap2-bin for capsh (usually
        installed anyway, but make them explicit to be sure).
      + debian/chrony.default: new option SYNC_IN_CONTAINER to not fall back
        (Default off) [fixed a minor typo in the comment in this update]
      + debian/chronyd-starter.sh: wrapper to handle special cases in containers
        and if CAP_SYS_TIME is missing. Effectively allows to run NTP server in
        containers on a default installation and avoid failing to sync time (or
        if allowed to sync, avoid multiple containers to fight over it by
        accident).
      + debian/install: make chrony-starter.sh available on install.
      + debian/docs, debian/README.container: provide documentation about the
        handling of this case.

 -- Christian Ehrhardt <email address hidden> Thu, 12 Mar 2020 11:02:33 +0100