compile red and red/system compilers from source - red

Question

I've been looking to evaluate the red programming language - red-lang.org
While it is nice that you can obtain a working executable easily I prefer to compile things from source. It is less obvious how to do that for red.
The instructions ask you to download a rebol compiler/intepreter which is itself just an executable.
If you do that it works but it screams "don't do that" very loudly.
rebol> do/args %red.r "-v 2 %tests/hello.red"
will compile hello world but how do you bootstrap the red compiler itself?
1. Assuming you have rebol how do build the 'red' executable?
aside: Are the authors aware that there is a program called 'red' installed on many Linux boxes already (a version of the ancient ed program)?
I thought this might be done by:
rebol> do/args %red.r "-r %environment/console/console.red"
but "console" is not the executable also known as 'red' it doesn't support the same commmand line options such as -c to compile.
2. Assuming the proper way to do this involves bootstrapping from rebol (rather than C or something else) how do you build (a suitable) rebol from source?
I would like to build both red and red/system or any other interesting variants.
This question mentions a youtube video but is there something written down somewhere?
This seems like the sort of thing than ought to be near the front of the documentation to me.

Answer 1

I asked a similar question in their Google Group about a year back.
https://groups.google.com/forum/#!topic/red-lang/zZ3jEeNJ5aI
The short answer is this ...
The current “bootstrap” Red compiler is written in Rebol. Rebol is not compilable. The downloadable Red binaries are not compiled but encapsulated (containing both the compiler and a Rebol executable) using the Rebol Software Development Kit (SDK). The Rebol is SDK is a commercially licensed product that is probably not available any longer. (The REBOL SDK used by the Red team is properly licensed).
There are scripts and instructions on how to build a Red binary at https://github.com/red/red/tree/master/build
That said anything you can compile with the Red binary, you can compile with the source compiler. The source compiler is just as fast as the “binary” one. (As you know, the source compiler happily runs under free Rebol versions that are still easily available.) In fact, the red team uses the source compiler not the “binary” one.
So until the self-hosted Red compiler is available, there are two basic options:
if you want to use the Red binary, get it from the automated builds
if you want the absolute, up to the minute compiler, use it in source form.
Hope this helps.
Peter