@delacroix fixparts went missing from FOS during a Buildroot update. The fix (fos#195) landed yesterday, and the first build with it is EXP_20261021-160109. I checked that release: /usr/sbin/fixparts is present in init.xz, init_32.xz, and arm_init.cpio.gz.
Your debug task boots the init that your FOG server serves, not the one you downloaded. Put the new file in place on the server:
cd /var/www/html/fog/service/ipxe mv init.xz init.xz.old wget https://github.com/FOGProject/fos/releases/download/EXP_20261021-160109/init.xz sha256sum init.xzThe hash must match the init.xz.sha256 on the release page (it starts 8e3457ad4268add5). To check the content without a boot:
xz -dc init.xz > /tmp/init.img debugfs -R "ls -l /usr/sbin" /tmp/init.img | grep fixpartsThen run the capture again. If fixparts is in that listing and the capture still fails, please post the output of fixparts /dev/sdX (or /dev/nvme0n1) from a debug task.