Pamac creates it’s own working folder /var/tmp/pamac which contains a folder dbs where the ocntent of dbs/sync is a separate copy of the the pacman databases and dbs/local is a symlink to /var/lib/pacman/local.
Pamac does not create it’s own lock-file - it uses the libalpm lockfile located in /var/lib/pacman to avoid collision with pacman.
As the advise appears pointing to an non existing file - where and from whom does this advise originate?