Currently, the ReactOS version that One-Core-API builds off is old, from commit a315eeefe1e8c23c945e0816929a48eac82e6c10, or from August 4, 2017. (assuming "Fake merging" didn't change the version)
At the moment, the latest ReactOS commit that is compilable and stable is release/0.4.10. There have been 3315 commits since then.
Currently, the ReactOS version that One-Core-API builds off is old, from commit a315eeefe1e8c23c945e0816929a48eac82e6c10, or from August 4, 2017. (assuming "Fake merging" didn't change the version)
At the moment, the latest ReactOS commit that is compilable and stable is release/0.4.10. There have been 3315 commits since then.