* Package name    : abduco
  Version         : 0.6
  Upstream Author : Marc André Tanner <mat@brain-dump.org>
* URL             : http://www.brain-dump.org/projects/abduco/
* License         : ISC
  Programming Lang: C
  Description     : lightweight session manager with {de,at}tach support

abduco provides session management i.e. it allows programs to be run independently from its controlling terminal. That is programs can be detached - run in the background - and then later reattached. Together with dvtm it provides a simpler and cleaner alternative to tmux or screen.

This package was included in Debian for a short while but was removed
due to the Debian package maintainer being inactive. abduco has a number
of advantagers over dtach that are described in the homepage and is
significantly more maintained. dvtm, a package by the same developer, is
intended to be paired with abduco for many use cases and already exists
within Debian.

retitle 900387 ITP: abduco -- lightweight session {at,de}tach manager
owner 900387 Jayen Ashar <jayen@jayenashar.org>
thanks

I intend to package abduco for Debian. Source has been prepared and
builds cleanly under sid. A sponsor request will follow on
debian-mentors@.

Package: abduco
Version: 0.6
Upstream: https://www.brain-dump.org/projects/abduco/
License: ISC
Description:
 abduco provides session management - programs can be detached and
 reattached to/from a controlling terminal. Together with dvtm it offers
 a smaller alternative to tmux/screen, or it can stand alone as a dtach
 replacement.

Hi Marc,

I'm re-packaging abduco for Debian (the original RFP, #900387, has been
sitting open since 2018). The source has been built and uploaded to mentors
and an RFS bug has been filed; that part is fine.

Before it goes through Debian's NEW queue review, though, I wanted to flag
an old issue that will almost certainly come up: Bug #771102. In November
2014, Ned T. Crigler (dtach upstream) reported that abduco 0.1's packet
protocol and keyboard handling looked like a derived work of dtach (GPL-2+)
but was licensed as ISC. Axel Beckert ran similarity tools and confirmed
there were code locations that looked suspiciously similar. The bug was
open for 18 months without an upstream response, and the FTP Masters
removed abduco from the archive administratively in May 2016.

I've spent some time comparing current abduco 0.6 against dtach 0.8, and
the situation looks much better than it did in 2014:

  * The packet struct now uses unsigned int / size_t fields and a
BUFSIZ-sized buffer rather than the unsigned char fields and sizeof(struct
winsize) buffer that abduco 0.1 took from dtach.
  * The VSUSP / SIGTSTP suspend dance in the keyboard handler - which was
reproduced word-for-word in 0.1 - is gone.
  * The "\033[999H" EOS escape constant is gone.
  * Signal installation switched from signal(2) to sigaction(2).
  * The architecture is multi-client now (a Server with a linked list of
Clients) rather than dtach's single-attached-client model.

What's still shared are the message-type enum values (0..4: push, attach,
detach, winch/resize, redraw) and the overall packet shape (type, len,
union of buffer + winsize). I'm intending to call those out in
debian/copyright as functional / interface elements, with a note that the
verbatim sections from abduco 0.1 have been rewritten.

Two things I'd like your view on, if you have a minute:

  1. Would you consider adding a brief acknowledgement of dtach as prior
art in a source-file comment (or even a CREDITS file) upstream? README
already says abduco is similar to dtach - a one-liner in the source stating
it's protocol-compatible with dtach but otherwise an independent rewrite
would close a lot of the residual ambiguity.

  2. Do you have a position on Crigler's specific 2014 claims that I can
quote in debian/copyright? I'm putting the analysis above in there
regardless, but having even a one-paragraph statement from you - "the
verbatim sections were unintended, they're gone now, the protocol shape is
convergent design" or similar - would be much stronger than my third-party
reading of the diff.

If you'd rather not engage with this, that's also fine - I'll proceed with
my own analysis in debian/copyright and let the FTP Masters decide. I just
wanted to give you the chance to weigh in.

In any case, thanks for abduco.

  Jayen Ashar <jayen@jayenashar.org>

We believe that the bug you reported is fixed in the latest version of
abduco, 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 900387@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Jayen Ashar <debian@jayenashar.org> (supplier of updated abduco 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: Tue, 09 Jun 2026 19:09:21 +1000
Source: abduco
Binary: abduco abduco-dbgsym
Architecture: source amd64
Version: 0.6-1
Distribution: unstable
Urgency: medium
Maintainer: Jayen Ashar <debian@jayenashar.org>
Changed-By: Jayen Ashar <debian@jayenashar.org>
Description:
 abduco     - lightweight session attach/detach manager
Closes: 900387
Changes:
 abduco (0.6-1) unstable; urgency=medium
 .
   * Initial release (Closes: #900387).
     Reintroduces abduco, removed in 2016 over Bug #771102 (alleged dtach
     code reuse); see d/copyright for how the flagged loci have been
     rewritten or removed in abduco 0.6 and what remains shared.
   * d/rules: enable hardening=+all (adds bindnow), pulling the flags in via
     /usr/share/dpkg/buildflags.mk so the maint option is actually honoured;
     a direct $(shell dpkg-buildflags ...) did not see it and dropped bindnow.
   * d/control: drop comma-without-space synopsis (lintian
     odd-mark-in-description).
   * d/copyright: document the 2016 removal over Bug #771102 (alleged dtach
     code reuse), and how the loci flagged then have been substantively
     rewritten or removed in abduco 0.6 (packet struct field widths and
     buffer size, VSUSP / SIGTSTP suspend dance, "\033[999H" EOS constant,
     sigaction vs signal, multi-client server). Notes what remains shared
     (wire-protocol enum values, overall packet shape) and points at
     upstream's README acknowledgement of dtach as prior art.
   * d/copyright: use the full real name on the debian/* copyright line to
     match the Maintainer field.
   * d/control: point Vcs-* at salsa.debian.org/debian/abduco
     (the Debian-namespace packaging repo).
   * d/control: use a dedicated maintainer address (debian@jayenashar.org)
     to limit address harvesting from the published archive indices.
   * d/patches: add verbose-build.patch so the upstream Makefile prints the
     real compile/link commands; blhc reported NONVERBOSE BUILD and failed
     the Salsa CI hardening job.
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