Unikraft names the image after the VMM rather than the platform -- elfloader_qemu-x86_64, elfloader_fc-x86_64, elfloader_qemu-arm64 -- so the hard-coded elfloader_kvm-<arch> never existed and every build failed at the collect step after linking cleanly. Glob for elfloader_*-<arch> and require exactly one match, so a future naming change fails here rather than shipping the wrong file.