#17: make Ninja build backend a conditional mandatory requirement, and add make as a fallback.

[c-alpha]

PR #17 makes Ninja a requirement for building astroid.

I would like to propose to make ninja an option (with default enabled). Those who don't want to install ninja just to build astroid once could then use brew install astroid --without-ninja to build it using make.

I am aware that for development work fast turn-around times are important.

But from an end-user's perspective, there is no point in unconditionally requiring a particular build tool. Considering that a make of sorts being available on any system using homebrew is a fairly safe bet, IMHO, and that cmake generates build files for many backends, ninja being just one of them, I would maintain that a make build should always remain possible as a fallback solution and as a last resort.

[yeled]

How about -GNinja only if you are building --HEAD?

[c-alpha]

Brilliant idea!