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Though I'm using gcc normally for my > builds (but I see the tools/sched_ext/ build does use clang explicitly > for some things). Yeah, we explicitly use clang to build BPF code. I'm on CachyOS, which ships clang 22.1.8. In theory clang-19 should be enough... if you can mess up the VM maybe give it a try with clang 20? From the dump it really looks like the compiler failed to generate proper BPF code for arenas. Thanks, -Andrea