Are there any technical necessities for fant, fanp, jstub, and nstub to be implemented natively in sys?

Just an idle curiosity :)

Well fanp is actually implemented in compiler::Fanp - its a Fantom program.

Fant could be implemented in Fantom too, but since it is used as a core bootstrap thing it lives in sys.

The stub code is a command line wrapper for the emitter, so that would always be native.

Thanks.

Well fanp is actually implemented in compiler::Fanp - its a Fantom program.

Does this mean that src/sys/*/fanx/tools/Fanp.* is obsoleted?

Yeah it was obsolete, I removed it and reworked fanp to work like flux/fansh (which just use fan/fan.exe with an explicit main)