Hi,
I'm trying to change Boinc working dir from /var/lib to /home/boinc but it doesn't work; fail with "boinc-client.service: Changing to the requested working directory failed: No such file or directory".
After read many threads and guides I'm stuck. Please help needed...

What have I done? Here detailed steps
this is the status "working"; before any change

$ systemctl status boinc-client.service
	● boinc-client.service - Berkeley Open Infrastructure Network Computing Client
	Loaded: loaded (/lib/systemd/system/boinc-client.service; enabled; vendor preset: enabled)
	Active: active (running) since Thu 2018-11-29 20:28:09 CET; 13min ago
		Docs: man:boinc(1)
	Main PID: 1030 (boinc)
		Tasks: 2 (limit: 2320)
	CGroup: /system.slice/boinc-client.service
			└─1030 /usr/bin/boinc

	nov 29 20:37:33 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:33 [---] Resuming computation
	nov 29 20:37:43 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:43 [Einstein@Home] Sending scheduler request: To fetch work.
	nov 29 20:37:43 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:43 [Einstein@Home] Requesting new tasks for CPU
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] Scheduler request completed: got 0 new tasks
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] No work sent
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] see scheduler log messages on https://einsteinathome.org/host/12744781/log
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] Binary Radio Pulsar Search (Arecibo) is not available for your type of computer.
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] Gamma-ray pulsar search #5 needs 19.07MB more disk space.  You currently have 0.00 MB available a
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] BOINC will delete file l1_0426.80_O1C02Cl2In0 when no longer needed
	nov 29 20:39:40 gianni-fisso boinc[1030]: 29-Nov-2018 20:39:40 [---] Suspending computation - computer is in use

Stop client

$ systemctl stop boinc-client.service

$ systemctl status boinc-client.service
	● boinc-client.service - Berkeley Open Infrastructure Network Computing Client
	Loaded: loaded (/lib/systemd/system/boinc-client.service; enabled; vendor preset: enabled)
	Active: inactive (dead) since Thu 2018-11-29 20:45:14 CET; 10min ago
		Docs: man:boinc(1)
	Process: 2946 ExecStopPost=/bin/rm -f lockfile (code=exited, status=0/SUCCESS)
	Process: 2945 ExecStop=/usr/bin/boinccmd --quit (code=exited, status=0/SUCCESS)
	Process: 1030 ExecStart=/usr/bin/boinc (code=exited, status=0/SUCCESS)
	Main PID: 1030 (code=exited, status=0/SUCCESS)

	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] No work sent
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] see scheduler log messages on https://einsteinathome.org/host/12744781/log
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] Binary Radio Pulsar Search (Arecibo) is not available for your type of computer.
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] Gamma-ray pulsar search #5 needs 19.07MB more disk space.  You currently have 0.00 MB available a
	nov 29 20:37:48 gianni-fisso boinc[1030]: 29-Nov-2018 20:37:48 [Einstein@Home] BOINC will delete file l1_0426.80_O1C02Cl2In0 when no longer needed
	nov 29 20:39:40 gianni-fisso boinc[1030]: 29-Nov-2018 20:39:40 [---] Suspending computation - computer is in use
	nov 29 20:45:13 gianni-fisso systemd[1]: Stopping Berkeley Open Infrastructure Network Computing Client...
	nov 29 20:45:13 gianni-fisso boinc[1030]: 29-Nov-2018 20:45:13 [---] Received signal 15
	nov 29 20:45:14 gianni-fisso boinc[1030]: 29-Nov-2018 20:45:14 [---] Exiting
	nov 29 20:45:14 gianni-fisso systemd[1]: Stopped Berkeley Open Infrastructure Network Computing Client.

this is what I see under /var/lib before any change

:/var/lib$ ll -d bo*
	lrwxrwxrwx 1 boinc boinc   12 mag 22  2018 boinc -> boinc-client/
	drwxr-xr-x 5 boinc boinc 4096 nov 29 20:45 boinc-client/

copy data

:/var/lib$ sudo cp -a boinc-client /home/boinc/

$ ll /home/boinc/
	drwxr-xr-x 3 boinc boinc 4096 nov 29 20:50 ./
	drwxr-xr-x 8 root  root  4096 nov 24 10:35 ../
	drwxr-xr-x 5 boinc boinc 4096 nov 29 20:45 boinc-client/

hide original dir

:/var/lib$ sudo mv boinc-client boinc-client.ori

create symlink

:/var/lib$ sudo ln -s /home/boinc/boinc-client boinc-client

:/var/lib$ sudo chown -h boinc:boinc boinc-client

:/var/lib$ ll -d bo*
	lrwxrwxrwx 1 boinc boinc   12 mag 22  2018 boinc -> boinc-client/
	lrwxrwxrwx 1 boinc boinc   24 nov 29 20:52 boinc-client -> /home/boinc/boinc-client/
	drwxr-xr-x 5 boinc boinc 4096 nov 29 20:45 boinc-client.ori/

then start client

$ systemctl start boinc-client.service

but this is the result...

$ systemctl status boinc-client.service
	● boinc-client.service - Berkeley Open Infrastructure Network Computing Client
	Loaded: loaded (/lib/systemd/system/boinc-client.service; enabled; vendor preset: enabled)
	Active: [b]failed[/b] (Result: exit-code) since Thu 2018-11-29 21:10:19 CET; 23s ago
		Docs: man:boinc(1)
	Process: 3328 ExecStopPost=/bin/rm -f lockfile (code=exited, status=200/CHDIR)
	Process: 2945 ExecStop=/usr/bin/boinccmd --quit (code=exited, status=0/SUCCESS)
	Process: 3327 ExecStart=/usr/bin/boinc (code=exited, status=200/CHDIR)
	Main PID: 3327 (code=exited, status=200/CHDIR)

	nov 29 21:10:19 gianni-fisso systemd[1]: Started Berkeley Open Infrastructure Network Computing Client.
	[b]nov 29 21:10:19 gianni-fisso systemd[3327]: boinc-client.service: Changing to the requested working directory failed: No such file or directory[/b]
	[b]nov 29 21:10:19 gianni-fisso systemd[3327]: boinc-client.service: Failed at step CHDIR spawning /usr/bin/boinc: No such file or directory[/b]
	nov 29 21:10:19 gianni-fisso systemd[1]: boinc-client.service: Main process exited, code=exited, status=200/CHDIR
	[b]nov 29 21:10:19 gianni-fisso systemd[3328]: boinc-client.service: Changing to the requested working directory failed: No such file or directory[/b]
	[b]nov 29 21:10:19 gianni-fisso systemd[3328]: boinc-client.service: Failed at step CHDIR spawning /bin/rm: No such file or directory[/b]
	nov 29 21:10:19 gianni-fisso systemd[1]: boinc-client.service: Control process exited, code=exited status=200
	nov 29 21:10:19 gianni-fisso systemd[1]: boinc-client.service: Failed with result 'exit-code'.

If I revert changes, all restart working perfectly

OS: KUbuntu 18.04
Boinc: 7.9.3 x86_64-pc-linux-gnu

systemd is probably limiting services' access to /home. Usually services have no business poking files there. I don't remember off hand what settings change that. I suggest you read systemd manual pages about services and unit files.