nixos-19.09: directories test fails

[qknight]

In nixos-19.03 it was still working but in 19.09 it fails, starting with this commit:

The nixcloud test 'directories' has failed with error 'command `stat -c %U /super/n/e/s/t/e/d/owner.txt' did not succeed (exit code 1)' but in case the machine was too slow (virtualized, not enough ram, too much cpu load, etc) then you can also disable the tests by adding 'nixcloud.tests.enable = false;' to your /etc/nixos/configuration.nix and still use our software.
cleaning up
killing machine (pid 594)
(0.00 seconds)
Attempt to end element "nest" with "logfile" tag at /nix/store/6pby4z1h1068dd1zw3758ppglwlkanyf-nixos-test-driver/lib/perl5/site_perl/Logger.pm line 28.
END failed--call queue aborted, <__ANONIO__> line 270.
vde_switch: EOF on stdin, cleaning up and exiting
vde_switch: Could not remove ctl dir '/build/vde1.ctl': Directory not empty
builder for '/nix/store/gqzirha38kbm6z4vjppiipwnwx27q6kz-vm-test-run-directories.drv' failed with exit code 22
error: build of '/nix/store/gqzirha38kbm6z4vjppiipwnwx27q6kz-vm-test-run-directories.drv' failed
5b0db07ee1c86376755a7e91fc4d1cfda2a7cff6 is the first bad commit
commit 5b0db07ee1c86376755a7e91fc4d1cfda2a7cff6
Author: Jörg Thalheim <joerg@thalheim.io>
Date:   Fri Feb 22 08:23:48 2019 +0000

    systemd: 239.20190219 -> 241.20190221

 pkgs/os-specific/linux/systemd/default.nix | 59 ++++++++----------------------
 1 file changed, 16 insertions(+), 43 deletions(-)
bisect run success