Comment 30 for bug 1852747

@legioner

# build logs
dh_installsystemd -pmdadm mdcheck_continue.timer mdcheck_start.timer mdmonitor-oneshot.timer
dh_installsystemd: error: Package 'mdadm' does not install unit ''.
make: *** [debian/rules:88: binary-arch] Error 25
dpkg-buildpackage: error: fakeroot debian/rules binary subprocess returned exit status 2

debhelper src code:
    355 # This hash prevents us from looping forever in the following
    356 # while loop. An actual real-world example of such a loop is
    357 # systemd's systemd-readahead-drop.service, which contains
    358 # Also=systemd-readahead-collect.service, and that file in turn
    359 # contains Also=systemd-readahead-drop.service, thus forming an
    360 # endless loop.
    361 my %seen;
    362
    363 # Must use while and shift because the loop alters the list.
    364 while (@args) {
    365 my $unit = shift @args;
    366 my $path = "${tmpdir}/lib/systemd/system/${unit}";
    367
    368 error("Package '$package' does not install unit '$unit'.") unless (-f $path);

I need to investigate what dh_installsystemd doesn't like about this.