[cfe-dev] Cannot CMake self-hosted clang on Windows for lack of libxml2

[Ben Boeckel via cfe-dev]

On Mon, Aug 23, 2021 at 15:17:21 -0700, Adrian McCarthy via cfe-dev wrote:
> Yikes!  Thanks for the heads up.
> 
> This is the third time I've bisected to find build configuration problems
> that affect only certain Windows configurations only to learn that it was
> (primarily) a change in our tools that broke things (retroactively).  Since
> the bot configurations aren't updated very often, it's easy for these
> problems to go unnoticed for a very long time.

*Puts on CMake developer hat*

Could an issue please be filed about this? CMake tries hard to not break
backwards compat, though we're not perfect (and we can't fix what we're
not aware of).

> It's one thing not to have hermetic builds, but it's quite another to allow
> every developer to choose from a wide range of versions for each of the
> myriad tools necessary to build the product.  The builds are so sensitive
> to so many details of the environment, it's rather amazing to me how often
> we manage to succeed.

Yes, and CMake tries not to be the bump in the road there, but we can
fix this in 3.20.6 and 3.21.2 (maybe 3.21.3, depends on how intricate
the fix is).

Thanks,

--Ben