Comment 8 for bug 1641615

Considering the facts so far:
- it seems racy
- works mostly even in LP chroot based build envs
- fails ?almost? always on LP
- in the past it had an issue with concurrency
- I had some (very limited) success to crash it similarly (not the same) by running more tests at once

=> consider it might be concurrency on the tests.
Currently we have:
 dh_auto_test -O--builddirectory=/<<PKGBUILDDIR>>/debian/build
[...]
 make -j4 check VERBOSE=1

Lets shrink that on the tests to be non concurrent and see again on LP if it works there reliably.

Evaluated on a ppa and I got 4/4 successful builds:

https://launchpad.net/~paelzer/+archive/ubuntu/libvirt-bug-1633207/+build/11203972/+files/buildlog_ubuntu-zesty-amd64.libvirt_2.1.0-1ubuntu11~ppa1_BUILDING.txt.gz
https://launchpad.net/~paelzer/+archive/ubuntu/libvirt-bug-1633207/+build/11203973/+files/buildlog_ubuntu-zesty-i386.libvirt_2.1.0-1ubuntu11~ppa1_BUILDING.txt.gz
https://launchpad.net/~paelzer/+archive/ubuntu/libvirt-bug-1633207/+build/11204090/+files/buildlog_ubuntu-zesty-amd64.libvirt_2.1.0-1ubuntu11~ppa2_BUILDING.txt.gz
https://launchpad.net/~paelzer/+archive/ubuntu/libvirt-bug-1633207/+build/11204091/+files/buildlog_ubuntu-zesty-i386.libvirt_2.1.0-1ubuntu11~ppa2_BUILDING.txt.gz

In these logs one can also see that the build itself works just fine with many cpus
make -j4
but later on the test is called via dh_auto_test with
make -j1

So that works in 4/4 cases, ready to upload as FTBFS fix and cross fingers that it works in this upload as tested on the ppa and not staying the recreation nightmare it was so far.