I want to know if it's possible use HarfTeX/LuaHBTeX with ConTeXt (MKIV),
mainly for what can be done with them (the "mode=harf" feature and Lua
language features).
Although this is pretty easy with LaTeX:

\usepackage{harfload}
\setmainfont{font}[RawFeature={mode=harf}]

I have no idea of how to make it work with context. I've tried the
following with a test file (a simple \starttext .. \stoptext document):

context tests.tex --engine=luahbtex

And this happens:

mtx-context     | run 1: luahbtex
--fmt="/home/coragyps/.texlive2019/texmf-var/luatex-cache/context/a86c089b384a3076dc514ba966a1fac9/formats/luatex/cont-en"
--jobname="tests"
--lua="/home/coragyps/.texlive2019/texmf-var/luatex-cache/context/a86c089b384a3076dc514ba966a1fac9/formats/luatex/cont-en.lui"
--c:currentrun=1 --c:engine="luahbtex" --c:fulljobname="./tests.tex"
--c:input="./tests.tex" --c:kindofrun=1 --c:maxnofruns=9
--c:texmfbinpath="/usr/local/texlive/2019/bin/x86_64-linux" "cont-yes.mkiv"

This is LuaHBTeX, Version 1.11.2 (TeX Live 2020/dev)
 system commands enabled.

(Fatal format file error; I'm stymied)mtx-context     | fatal error: return
code: 256

What should I do? Thank you in advance