Systemd service unit not starting at boot unless #[Unit] is commented out

Question

Running up to date Arch Linux ARMv7 (RaspPi 3). I have two systemd service units which I have created. I want foo to start first and then bar. foo starts on boot and bar does not. However bar will start manually from a shell prompt. Here is a copy of the bar unit file:

[Unit]
Requires=foo.service
After=foo.service

[Service]
Type=simple
ExecStart=/usr/bin/setsid /usr/bin/bar >/dev/null 2>&1 < /dev/null
TimeoutSec=0
RemainAfterExit=Yes

[Install]
WantedBy=getty.target

However if I put a pound symbol in front of [Unit] like so:

#[Unit]

Then bar starts at boot in the right order (after foo).

This behaviour and commenting out of the [Unit] line doesn't seem to make sense or fit in with the documentation I can find. So I'm just wondering why it makes the unit start at boot?!

Answer 1

Commenting out [Unit] causes the Requires and After directives to be ignored. Removing those directives and removing the comment # gives identical behaviour.

The reason it was not starting at boot without the comment # must be because of an issue with the requirement for the other service.