GitHub uses PCRE as the regex engine and doesn't allow variable length lookbehinds `(?<=a+)` <img width="1095" height="663" alt="Image" src="https://github.com/user-attachments/assets/56630420-6843-4beb-b445-ae1efd38e858" />
GitHub uses PCRE as the regex engine
and doesn't allow variable length lookbehinds
(?<=a+)