[DONOTMERGE] Switch llvm source build to v20

[Zentrik]

This is for testing with pkgeval before we have built on yggdrasil

@nanosoldier runtests(configuration = (buildflags=["LLVM_ASSERTIONS=1", "FORCE_ASSERTIONS=1", "USE_BINARYBUILDER_LLVM=0"],), vs_configuration = (buildflags=["LLVM_ASSERTIONS=1", "FORCE_ASSERTIONS=1"],))

[maleadt]

PkgEval got restarted:

@nanosoldier runtests(configuration = (buildflags=["LLVM_ASSERTIONS=1", "FORCE_ASSERTIONS=1", "USE_BINARYBUILDER_LLVM=0"],), vs_configuration = (buildflags=["LLVM_ASSERTIONS=1", "FORCE_ASSERTIONS=1"],))

Only one job ahead of this, so it should report within 2 days.

[maleadt]

The build failed:

CMake 3.20.0 or higher is required.  You are running version 3.18.4

PkgEval is currently using the latest rootfs, https://github.com/JuliaCI/rootfs-images/releases/tag/v7.10. I guess we'll need to upgrade from bullseye to bookworm, https://github.com/JuliaCI/rootfs-images/blob/e7be8086ff1285b0f333ca72884977d01aed0e1f/src/build_img/debian.jl#L17.

[giordano]

You can download cmake with contrib/download_cmake.sh, but no idea how do that for pkgeval invocations (if doable at all). But maybe the Makefile here can be hacked to force that.

[nanosoldier]

Your job failed. Consult the server logs for more details (cc @maleadt).

[Zentrik]

I forgot we added an invocation to the download cmake script for the source build, JuliaCI/julia-buildkite@552037b.

[Zentrik]

@maleadt would it be easy to get this fixed otherwise I'll start the llvm yggy build?

[giordano]

Can't you run the download cmake script as part of the build script in this PR? This is just for testing anyway.

[Zentrik]

Can't you run the download cmake script as part of the build script in this PR? This is just for testing anyway.

Yep, ignore me then tim, I'll do that.

[Zentrik]

Let's see if this works

@nanosoldier runtests(configuration = (buildflags=["LLVM_ASSERTIONS=1", "FORCE_ASSERTIONS=1", "USE_BINARYBUILDER_LLVM=0"],), vs_configuration = (buildflags=["LLVM_ASSERTIONS=1", "FORCE_ASSERTIONS=1"],))