There are many issues which I should check and solve.
But, I mainly try to implement SPVM project. This improve Perl performance significantly. This is important for Perl future.
https://github.com/yuki-kimoto/SPVM
Until implementing main part of SPVM , I need 1 - 2 years.
Sorry, I can't have the enough time to fix GitPrep now.
I'm happy for you to solve the bug of GitPrep if you need to fix it early time.