There are ongoing discussions on this:
- COMP: Disabling git protocol by default by RafaelPalomar · Pull Request #5980 · Slicer/Slicer · GitHub
- 2021.11.02 Weekly Meeting
I’m currently testing if configuring with Slicer_USE_GIT_PROTOCOL=OFF is a workaround for a complete build while this is sorted out. I’ll post my findings here