Re: can BUILD_REQUIRES atoms include a version

On 12/08/2025 07:17, Jeremy Drake via Cygwin-apps wrote:
> clang and lld require the matching version of llvm to build against.  The
> named libllvm20.1 package for the library itself is nice for runtime, but
> how do I ensure that scallywag pulls in the correct libllvm-devel (and
> libpolly-devel), especially while they are still test versions?

Yeah, none of this works properly, yet.

In theory, there is a syntax for writing version constraints, defined in 
[1], so maybe you could write "llvm (>= 20, <21)" or something like that.

(It seems a bit under-specified how to deal with an "and" here)

But this would need to be understood by scallywag and passed through to 
setup, and setup would need to be able to told those constraints (at the 
moment it only understands "=" for an exact version-release match).

[1] https://sourceware.org/cygwin-apps/setup.ini.html

(as you noted, doing this via an explicitly numbered provide is 
possible, and works better when the version interval isn't known in 
advance: which occurs in a few places e.g. xf86-video-dummy requires 
xserver-video-abi25, because we can't know in advance what version of 
xserver that abi might change in)