Bionic autopkgtests failing due to stderr output present and not ignored

[Łukasz Zemczak]

This seems to be happening at least for i386, ppc64el and arm64:

II: Removing Fan Bridge...
de-configuring fan underlay:10.42.0.0/16 overlay:250.0.0.0/8
PASS
autopkgtest [23:52:05]: test lxd: -----------------------]
autopkgtest [23:52:05]: test lxd: - - - - - - - - - - results - - - - - - - - - -
lxd FAIL stderr: sd_bus_open_system: No such file or directory
autopkgtest [23:52:05]: test lxd: - - - - - - - - - - stderr - - - - - - - - - -
sd_bus_open_system: No such file or directory
autopkgtest [23:52:06]: @@@@@@@@@@@@@@@@@@@@ summary
docker PASS
lxd FAIL stderr: sd_bus_open_system: No such file or directory
Exit request sent.

[Andreas Hasenack (ahasenack)]

This happens because systemd-resolve --status $nic can be called in this loop before it's ready to answer:
       while [ $timeout -gt 0 ]; do
            dns2=$(systemd-resolve --status $nic1| \
                awk '/DNS Servers:/{print; exit}')
            if [ "$dns2" != "" ]; then
                break
            fi
            echo "$role: waiting for systemd resolver..."
            sleep 2
            timeout=$(( timeout - 2 ))
        done

We can see from the logs that in the second loop run (i.e., after 2s), it works already, or else it would have printed "$role: waiting for systemd resolver..." again:
Starting fanatic-test
lxd test: Waiting for addresses on eth0 ...
lxd test: Waiting for addresses on eth0 ...
lxd test: Waiting for addresses on eth0 ...
lxd test: Waiting for addresses on eth0 ...
lxd test: Waiting for addresses on eth0 ...
slave: detected primary route through eth0
sd_bus_open_system: No such file or directory
slave: waiting for systemd resolver... <----- just once, and the first time
slave: DNS: systemd(250.40.8.1)

The fix is to add 2>/dev/null to that systemd-resolve call, or allow for stderr in the dep8 test.

[Andreas Hasenack (ahasenack)]

This was fixed in 0.12.11 by adding allow-stderr to the dep8 restrictions. Last affected ubuntu release is bionic and earlier. Closing the bug.

[Andreas Hasenack (ahasenack)]

Actuall, the bug was specifically about bionic, so let's adjust the tasks.