dh-systemd seems not to support multiple service units

[Dererk]

Dear pkg-systemd Maintainers,

I've been trying to deliver a package that has a mix of enabled/disable
and started/not started service units.

The situation I encounter seems to be reflected at the manpage, when
calling dh_systemd_enable, quoting:

"Note that this command is not idempotent. dh_prep(1) should be called
between invocations of this command (with the same arguments).
Otherwise, it may cause multiple instances of the same text to be added
to maintainer scripts"

Which is exactly what I end up with, a really long postinst file
repeating the postinst instructions generated in the previous
dh_systemd_enable call

On the other hand, I may not be properly understanding the reference in
the manpage that states to trigger dh_prep between dh_system. If I
understand correctly, dh_prep will actually remove everything writing up
to that point into the respective debian/ directory's package entry,
which I double checked it does:

dh_prep --name=service_on_by_default
    rm -f debian/python3-mypackage.substvars
    rm -f debian/python3-mypackage.*.debhelper
    rm -rf debian/python3-mypackage/
    rm -f debian/binaries-pkg.substvars
    rm -f debian/binaries-pkg.*.debhelper
    rm -rf debian/binaries-pkg/
    rm -rf debian/tmp

What am I doing wrong? This is what the debian/rules looks like:

override_dh_systemd_enable:
    dh_systemd_enable --name=service_on_by_default
    dh_prep --name=service_on_by_default

    dh_systemd_enable --no-enable --name=non_tipical_service


Much appreciated,


Cheers,

Dererk