Fixes: #32428
This PR adds a dependency provider to depends builds.
A dependency provider allows overriding of cmake’s find_package() therefore giving total control over where dependencies come from in a build.
This achieves two things:
CMAKE_PREFIX_PATH breaking builds (i.e. 32428)
The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.
For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32595.
See the guideline for information on the review process. A summary of reviews will appear here.
Opened in draft for feedback on approach.
There is also a bypass for the boost package (in cmake/module/AddBoostIfNeeded.cmake) which I’d like to get working with the dependency provider ideally.
Note that this also bumps the minimum cmake version to 3.24.
Provides stronger guarantees about where dependencies come from during a (depends) build; i.e. only from depends.
Can you elaborate on this? Currently, CMake configured with a depends toolchain, should never look outside depends (doing so would be a bug). What are the stronger guarantees?
Provides stronger guarantees about where dependencies come from during a (depends) build; i.e. only from depends.
Can you elaborate on this? Currently, CMake configured with a depends toolchain, should never look outside depends (doing so would be a bug). What are the stronger guarantees?
Right, perhaps I didn’t use the best wording here.
When using the toolchain I have not found us pulling in extraneous deps from outside of depends, but have encountered us missing dependencies from inside of depends, e.g. in my original issue.
By using a dependency provider and intercepting calls to find_package(), as I understand it, we are getting even more control over which packages can be found than when using the toolchain.
This is what I termed “stronger guarantees”, perhaps misleadingly!
The windows job fails as currently we activate the dependency provider automatically based on whether a(ny) toolchain is in use.
This works fine for depends, but doesn’t make sense on windows where the vcpkg toolchain is used, without depends.
The idea for doing it this way was to try and avoid users having to pass two flags in order to build from depends – a toolchain and a dependency-provider – but perhaps this is necessary after all…
I do recall reading somewhere in cmake docs that choice of dependency provider should always be left to the user too, so I suppose doing it this way would fit with that.
Pushed an update which now only activates the dependency provider when using the depends toolchain.
This will hopefully appease the windows CI job, as well as making more sense in general and being more expected behaviour.
