One fixes building without `HWCAP_CPUID`, and one without `ESR_MAGIC`/`esr_context`. The case with `HWCAP_CPUID` is quite recent. The one about `ESR_MAGIC`/`esr_context` has been around for many years. I submitted a patch about it to wine-devel in 2020, but that patch was much more complex (bringing back the old codepath from before 85c01202ac70af0c83f894d7a8986adf66983459, and a configure test). In the simplest form, just omit the reference to `esr_context` and `ESR_MAGIC` and return 0, instead of attempting any heuristics about the kind of access violation. It's not perfect, but should hopefully be less of a burden to carry around, for being able to build with ancient headers. (In this case, I'm building with an old cross sysroot, for an old SBC, with an old distribution, where I run wine. The install on the SBC is new enough to have `esr_context` itself, but the cross sysroot/toolchain happens to bundle even older kernel headers.) -- https://gitlab.winehq.org/wine/wine/-/merge_requests/11114