Possible In-memory repository regression?

So I'm trying to get my branch updated with master https://github.com/Zoxive/libgit2sharp/tree/zoxive/refdb/ which revives the pluggable RefDb backend (#1226)

I've gotten through all the compile issues rebasing it up to the latest with dotnet core, and the codegen stuff. (Took a while to figure out that I had to change all the NativeMethod funcs to use the new custom marshaler)

Anyways all compiles and stuff now.. but testing my changes im running into an error that appears to be coming straight from libgit2.

LibGit2SharpException: path cannot exist in repository

It happens when i have an in memory repository and an OdbBackend.

Heres a sample unit test that shows the problem.
https://github.com/Zoxive/libgit2sharp/commit/7957581353134c17deaa71714ffd24a0a6130c5e

I did see that libgit2 had a regression (https://github.com/libgit2/libgit2/pull/4263) @ethomson fixed.
I'm guessing its related?

首先，使用記憶體中的 repository 和 OdbBackend 執行 commit 7957581353134c17deaa71714ffd24a0a6130c5e 中的範例單元測試。將此失敗與 libgit2 pull request 4263 進行比較，並追蹤「path cannot exist in repository」例外在哪裡被拋出。完成的標準是重現成功，且不會使其他 repository backend 發生回歸。