[build2] Where to find config options?

[Boris Kolpackov]

Klaim - Joël Lamotte <mjklaim at gmail.com> writes:

> So maybe there is some heuristics you could extract from one of these
> projects assuming there is a config info of specific toolset?

Clang is also one of those tools that has "some heuristics" for
discovering MSVC. Some time ago there was a thread on this on
Clang's mailing list from which it's pretty clear the thing got
so complex and convoluted that nobody really understands how and
why it does what it does:

http://lists.llvm.org/pipermail/cfe-dev/2017-August/055022.html

I definitely want to avoid the same situation in build2. So I
think let's start with the configure in the dev command prompt
as a first step since anything more advanced will be built on
this.

Boris