When HISTTIMEFORMAT is set and history file truncation is performed, the first line of the history file (i.e. the timestamp of the first entry) seems to always be missing
> /tmp/hist HISTTIMEFORMAT= HISTFILESIZE=3 HISTFILE=/tmp/hist bash --norc -in <<<$'1\n2\n3' $ cat /tmp/hist 1 #1679274410 2 #1679274410 3
