[LLVMdev] [RFC] Raise minimum required CMake version to 3.0

[Robinson, Paul]

> > We don't require users to compile their own gcc. Are you saying it's
> > impossible to get pre-built CMake 2.8.12 and gcc 4.7 on either Mac or
> > Windows?
> 
> And we wouldn't be requiring it for cmake. My point was that cmake is
> always easier to install:
> 
> * From binaries: a bit easier, since they are provided in
> http://www.cmake.org/
> * From source: way easier than gcc.
> 
> Gosh, from my experience *building* cmake is easier than *downloading*
> llvm and clang in the right layout, so the extra cost is really small.

Enough "really small" costs add up to too much.  Not so long ago it took
me a couple days to get the right versions of enough packages sorted out
(on Linux) so that I could get the thing I actually wanted to work.  I
had to want it pretty badly to get through that. I wouldn't wish that on
anybody.  Probably makes me over-sensitive to prerequisite costs but...
not something to require lightly.
--paulr