I ran boinc many many years ago when it was v5. 

I got interested again so I installed 

boinc-manager-7.9.3-1.fc28.x86_64
boinc-client-7.9.3-1.fc28.x86_64

and later noticed that it was using /var/lib/boinc
I don't want boinc running under /var so i moved boinc to /home/boinc and
that broke everything.

The location of where the boinc directory/location is should be an option and easily moved from location to location at anytime without breaking anything.

I changed the home path for boinc in /etc/passwd.

I ran:
semanage fcontext -a -e /var/lib/boinc /home/boinc
restorecon -R -v /home/boinc 

and that didn't fix it.

i've googled high and low and have been unable to find a solution for this.

every time i 
systemctl start boinc-client.service

the result is:

● boinc-client.service - Berkeley Open Infrastructure Network Computing Client
   Loaded: loaded (/usr/lib/systemd/system/boinc-client.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2018-05-07 19:41:11 EDT; 9min ago
     Docs: man:boinc(1)
  Process: 9217 ExecStopPost=/bin/rm -f lockfile (code=exited, status=200/CHDIR)
  Process: 9216 ExecStart=/usr/bin/boinc (code=exited, status=200/CHDIR)
 Main PID: 9216 (code=exited, status=200/CHDIR)

May 07 19:41:11 homelnx.markpreston.me systemd[1]: Started Berkeley Open Infrastructure Network Computing Client.
May 07 19:41:11 homelnx.markpreston.me systemd[9216]: boinc-client.service: Changing to the requested working directory failed: No such file or directory
May 07 19:41:11 homelnx.markpreston.me systemd[9216]: boinc-client.service: Failed at step CHDIR spawning /usr/bin/boinc: No such file or directory
May 07 19:41:11 homelnx.markpreston.me systemd[1]: boinc-client.service: Main process exited, code=exited, status=200/CHDIR
May 07 19:41:11 homelnx.markpreston.me systemd[9217]: boinc-client.service: Changing to the requested working directory failed: No such file or directory
May 07 19:41:11 homelnx.markpreston.me systemd[9217]: boinc-client.service: Failed at step CHDIR spawning /bin/rm: No such file or directory
May 07 19:41:11 homelnx.markpreston.me systemd[1]: boinc-client.service: Control process exited, code=exited status=200
May 07 19:41:11 homelnx.markpreston.me systemd[1]: boinc-client.service: Failed with result 'exit-code'.
~


I can login to the boinc account and run the client.  but even then there are issues with boinc-manager in that it doesn't honor run preference, network preference, can't see disk usage.  It will reset the project if suspended or "no new tasks" after about 15 minutes.

If i'm stuck with using /var then i won't be supporting boinc in the future.