I've updated partman's wiki page with information
I couldn't find in the official documentation:

https://wiki.debian.org/DebianInstaller/Partman

`$bios_boot{ }` appears to be an old option, and I can't
find any evidence `$gptonly{ }` was ever actually implemented.
If you would rather not mention that sort of thing in
partman-auto-recipe.txt, could you link to the wiki page instead?
That should let users find the page, but understand it's less official.

I am quite new to partman-auto but have never seen any of these.
Do you have any evidence that '$bios_boot{ }' was ever implemented ?

'method{ biosgrub }' is just a regular specifier (creates an arbitrary
file in the partition directory) among many others, why specifically
mention it ?

I opened a merge request against debian-installer to update
partman-auto-recipe.txt with missing descriptions and some clarifications:
<https://salsa.debian.org/installer-team/debian-installer/-/merge_requests/66>

I haven't found any reference to it in the source code,
but bug #491376 comment #47 says:

    The correct approach here, I think, is to use a partman method instead.
    That ensures that a partition can contain a filesystem or a BIOS boot
    area, but not both. This also makes preseeding a lot easier - we don't
    need a special-cased $bios_boot{ } internal specifier any more, but can
    just set the method in the natural way.

... so it seems to have existed back in 2009.  More importantly, I've found
both `$bios_boot{ }` and `$gptonly{ }` recommended around the Internet,
but never found a definitive statement about what they're supposedly about.

I wouldn't mind these being added to the official documentation, but I went to
the wiki first because that seems like the more obvious place for documentation
that's basically just debunking urban legends.

`partman-auto-recipe.txt` mentions the following:

method{ format } - described in that file
method{ swap } - described in passing
method{ keep } - described in passing
method{ lvm } -	seems to make sense in context
method{ newworld } - seems to make sense in context
method{ efi } - seems to make sense in context

`method{ biosgrub }` is worth knowing about, but not mentioned there.
If there are others missing, they should be documented too :)

That looks much better!  I'll register for a Salsa account and try to
participate in the actual MR discussion, but here are some specific nitpicks:

I think this means the setting will be ignored, not that the partition
will be zeroed.  If so, maybe s/stripped/ignored/?

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=491376#47

Pascal Hambourg <pascal@plouf.fr.eu.org> wrote (Sun, 20 Jul 2025 09:29:43 +0200):

Just merged; thanks!

We believe that the bug you reported is fixed in the latest version of
debian-installer, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1109467@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Cyril Brulebois <kibi@debian.org> (supplier of updated debian-installer package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Sun, 28 Jun 2026 14:35:55 +0200
Source: debian-installer
Architecture: source
Version: 20260628
Distribution: unstable
Urgency: medium
Maintainer: Debian Install System Team <debian-boot@lists.debian.org>
Changed-By: Cyril Brulebois <kibi@debian.org>
Closes: 1109467 1118488
Changes:
 debian-installer (20260628) unstable; urgency=medium
 .
   [ Cyril Brulebois ]
   * Add fakeroot to Build-Depends:
      - It's used explicitly in various locations so it makes sense to have
        in the first place.
      - Additionally, that seems to have become needed for daily builds
        following commit 234b6db2c041cd605ade7bb7ef9c6f77d4841726 in
        dsa-puppet.git, with setup-dchroot only installing fakeroot for
        bullseye, bookworm, and trixie now. In other words, it's no longer
        installed by default in sid chroots available on porterboxes, where
        daily builds are performed.
   * Bump Linux kernel ABI to 7.0.13+deb14.
   * Adjust linux-image build-deps accordingly.
   * Switch kernel udeb from kernel-image-* to linux-binary-*, matching
     changes on the kernel side.
   * Update translation-status.
   * Upload to unstable as requested by Jochen Sprickerhof and Holger
     Levsen from the reproducible builds team.
 .
   [ Pascal Hambourg ]
   * Update doc/devel/partman-auto-recipe.txt. Closes: #1109467
 .
   [ Jochen Sprickerhof ]
   * Use fakeroot instead of Rules-Requires-Root: binary-targets, this makes
     the package not FTBFS with debrebuild and on reproduce.debian.net.
   * build/util/gen-tarball: make tarball reproducible.
 .
   [ Simon McVittie ]
   * artwork: Drop the version from the Ceratopsian boot screen, so d-i
     snapshots don't identify themselves as Debian 13.
     Similarly, remove the "11" from the Homeworld artwork for completeness.
     Closes: #1118488
 .
   [ John Paul Adrian Glaubitz ]
   * loong64: Add configuration for cdrom-based gtk installer
   * loong64: Add pkg-list for cdrom-based gtk installer
   * loong64: Remove DEBIAN_RELEASE override for Debian Ports
   * loong64: Remove KEYRING override for Debian Ports
   * loong64: Remove USE_UNRELEASED override for Debian Ports
   * loong64: Remove debian-ports-archive-keyring-udeb from pkg-lists
   * loong64: Add loong64 to the list of RELEASE_ARCHES
   * loong64: Add netboot flavour using a mini.iso
   * loong64: Remove debian-ports-archive-keyring from Build-Depends
   * riscv64: Remove debian-ports-archive-keyring from Build-Depends
   * loong64: Add initial pkg-list for netboot
 .
   [ Alper Nebi Yasak ]
   * Clamp mtimes of files included in mini.iso images
   * Normalise permissions of files included in mini.iso images
   * gen-tarball: Normalise file permissions
   * Set invariant mode, volume ID and label for mkfs.msdos calls
   * Use gen-tarball to generate armhf tarballs
   * Use xorriso to isohybridize x86 mini.iso images
   * Make seagate network-console uInitrd reproducible
   * Set C.UTF-8 locale for bdftobogl calls
   * Use pseudorandom volume ID for FAT filesystems
   * gen-hd-image: Use pseudorandom label IDs
   * Add debian-installer-images tarball to CI reprotest artifacts
 .
   [ Samuel Thibault ]
   * Add KERNEL_NAME variable to configure the kernel package base name.
 .
   [ Arnaud Rebillout ]
   * Drop arm64 cdrom depthcharge image for gru and hana boards. Their 32
     MiB size limit has been known from the get-go, and it's no longer
     possible to fit everything in.
 .
   [ Holger Wansing ]
   * Target forky for installer.
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