使用网易云课程《Perl语言高级编程》中老师的同款perl脚本做SSR查找及引物设计时出现的问题：unescaped left brace in regex is deprecated here(and will be fatal in Perl 5.30),passed through in regex;marked by <-- HERE in m/([ACGT]{2})\1{ <-- HERE 0.5}/ at ../primer_design/my_misa.pl.txt line 126,<IN> chunk2.是怎么回事？需要怎么解决？