# ISO Build Rules ## Verify package names before use ISO builds take 30–60 minutes. A wrong package name wastes an entire build cycle. **Rule: before adding any Debian package name to the ISO config, verify it exists and check its file list.** Use one of: - `https://packages.debian.org/bookworm/` — existence + description - `https://packages.debian.org/bookworm/amd64//filelist` — exact files installed - `apt-cache show ` inside a Debian bookworm container This applies to: - `iso/builder/config/package-lists/*.list.chroot` - Any package referenced in `grub.cfg`, hooks, or overlay scripts (e.g. file paths like `/boot/memtest86+x64.bin`) ## Example of what goes wrong without this `memtest86+` in Debian bookworm installs `/boot/memtest86+x64.bin`, not `/boot/memtest86+.bin`. Guessing the filename caused a broken GRUB entry that only surfaced at boot time, after a full rebuild.