$ perl pm_11133064_pack_test.pl
OS: cygwin; Perl: v5.34.0;
usequadmath='undef';
nvtype='double';

TEMPLATE: d
3333333333330340
TEMPLATE: d<
3333333333330340
TEMPLATE: d>
4003333333333333
TEMPLATE: D
Can't find string terminator "'" anywhere before EOF at -e line 1.
TEMPLATE: D<
Can't find string terminator "'" anywhere before EOF at -e line 1.
TEMPLATE: D>
Can't find string terminator "'" anywhere before EOF at -e line 1.