mkvfx was a project that maintained a comprehensive set of build recipes for the vfx ecosystem, across linux, mac, and windows.
The introduction of breaking changes at a fundamental level in core technologies, the pending migration from tbb to OneTBB is one example amongst many, mean that a significant effort is required to refresh and rewrite these scripts as core libraries are updated.
Until such a time as these technologies stabilize, mkvfx will be unavailable. Please feel free to use the discussions at the vfxpro99 fork of mkvfx for guidance or questions on porting or building vfx related technologies.