HISTDB_FILE seemingly not set

[maxthomas]

fresh install install using the suggested oh-my-zsh plugin dir and after adding commands to ~/.zshrc:

Error: incomplete SQL: PRAGMA user_version = 2
error in
History database /home/max/.histdb/zsh-history.db is using an older schema (0) and will be updated to version 2.
Backing up database to /home/max/.histdb/zsh-history.db-1563991992.bak before migration
cp: missing destination file operand after '/home/max/.histdb/zsh-history.db-1563991992.bak'
Try 'cp --help' for more information.
Update successful (you may want to remove the backup)

it looks like HISTDB_FILE isn't being set correctly - but i'm not sure.

there's also no backup present, so that flow looks incorrect.