Rebol was initially designed by Carl Sassenrath in 1997 as a closed source.
Its 3rd version was  open sourced in 2012, but abandoned by Carl just after
a few years. I am still maintaining sources in a separate fork:
https://github.com/Oldes/Rebol3

As I am not familiar with Debian packaging, I am trying to find some help
this way.
The main issue probably is that Rebol sources are partially generated using
Rebol itself. I can provide a pre-generated version for stage0.

Other links:
[1] http://rebol.com/
[2] https://en.wikipedia.org/wiki/Rebol
[3] https://github.com/rebol/rebol (original source files)

Thanks for any response,
Oldes