wantedBy not working when used from upstream systemd units #81138
Description
Describe the bug
I've noticed on several occasions, and again with a PR #81087 which has a unit
# tlp - systemd startup/shutdown service
#
# Copyright (c) 2020 Thomas Koch <linrunner at gmx.net> and others.
# This software is licensed under the GPL v2 or later.
[Unit]
Description=TLP system startup/shutdown
After=multi-user.target NetworkManager.service
Before=shutdown.target
Documentation=https://linrunner.de/tlp
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/nix/store/42m41jbsvbc7qh25k42cdc5jf2yjsf87-tlp-1.3.1/sbin/tlp init start
ExecStop=/nix/store/42m41jbsvbc7qh25k42cdc5jf2yjsf87-tlp-1.3.1/sbin/tlp init stop
[Install]
WantedBy=multi-user.target
The wantedBy didn't do anything when it was included with systemd.packages.
We had to add it manually like:
systemd.services.tlp.wantedBy = [ "multi-user.target" ];
Looking at nixpkgs, it seems like others have noticed this.