[llvm-dev] RFC: Updating to CMake 3.15.0

[David Chisnall via llvm-dev]

On 29/10/2019 18:00, Roman Lebedev via llvm-dev wrote:
> If you require The freshest version of something, it is all but guaranteed to
> be not packaged in distributions, so basically*everyone*  will have to
> work around the packaging system. If the version is //somewhat// aged,
> then it is not unreasonable to expect for it to be present in
> //some// proper packaged form in //most// distros.
> 
> All that of course does not apply to platforms with no native packaging
> system (windows?).

'Everyone' is overstating it a bit.  For the platforms that I use for 
LLVM-related work, the 3.15.4 release of CMake was available via the 
common package system on the following dates:

  - macOS, via Homebrew: 4 October, 2019.
  - Windows, via Chocolatey: 2 October, 2019
  - FreeBSD, via the package system on 5 October, 2019

It was tagged on 30 September, 2019 in CMake git (I presume it was then 
immediately released, but the CMake release notes and history page don't 
actually include dates), so that's a time from release to packaging of 
under a week for the slowest platform on that list.

Unless you're planning on moving to the new release on the day of the 
release, it will not be a problem for a large subset of the community.

The question if whether the cost of requiring people on platforms with 
lagging package sets to download a CMake binary or source tarball 
outside of their normal packaging infrastructure is higher than the cost 
of maintaining support for old versions of CMake.

David