data: tell systemd to create state directory
If the directory referred to by
ReadWritePaths= does not exist, the
service fails to start:
systemd: Starting Fingerprint Authentication Daemon... systemd: fprintd.service: Failed to set up mount namespacing: No such file or directory systemd: fprintd.service: Failed at step NAMESPACE spawning /usr/lib/fprintd/fprintd: No such file or directory systemd: fprintd.service: Main process exited, code=exited, status=226/NAMESPACE systemd: fprintd.service: Failed with result 'exit-code'. systemd: Failed to start Fingerprint Authentication Daemon.
This may happen when booting with an empty
For a system service,
any parent directories to be created if missing (with mode 0755 by
default, owned by the user and group of the service, which in this case
systemd.exec(5) does not say explicitly that, in combination
ProtectSystem=strict, the state directory will be mounted
read-write, but in fact it is.
I know that this will not do the right thing in the case where
@localstatedir@ is not
/var; I suppose one could specify both, and
ReadWritePaths= would be redundant in the common case.