memtest86+ postinst does not place files in /boot in a live-build chroot without grub triggers. Added fallback: extract directly from the cached .deb via dpkg-deb -x, with verbose logging throughout. Also remove "NVIDIA no MSI-X" from boot menu (premature — root cause unknown). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>