I think there's a problem with the new adb_errorlog pointing to /dev/null and wiping out /dev/null's special attributes.
Restarting adblock causes the file to become "normal". If I enable adb_debug which changes adb_errorlog to something besides /dev/null, it doesn't clobber the file. This is before and after a restart:
root@router:~# ls -l /dev/null; service adblock restart; sleep 5; ls -l /dev/null
crw-rw-rw- 1 root root 1, 3 Mar 4 21:27 /dev/null
-rw-r--r-- 1 root root 136 Mar 4 21:34 /dev/null
This was setting debug and everything was fine:
root@router:~# uci set adblock.global.adb_debug='1'
root@router:~# uci commit adblock
root@router:~# ls -l /dev/null; service adblock restart; sleep 5; ls -l /dev/null
crw-rw-rw- 1 root root 1, 3 Mar 4 21:27 /dev/null
crw-rw-rw- 1 root root 1, 3 Mar 4 21:27 /dev/null
This has unintended consequences of being unable to perform a sysupgrade. See my post at OpenWrt 25.12.0-rc5 - Release Candidate - #196 by dave14305
EDIT: I imagine this line removing adb_errorlog could be to blame when set to /dev/null?