Hello

studying how licensecheck works I found this file

t/exception/Cecill/tv_implementpoly.reference

which is under the

CeCILL-C with Sollya-4.1 exception

The license CeCILL is not compliant with the DFSG because of § 13.2


     Mandatory Choice of Venue (Article 13.2)

     The Clause: "Failing an amicable solution... disagreements or
     disputes shall be referred to the Paris Courts having jurisdiction..."
     DFSG Conflict: This is considered a "Choice of Venue" clause,
     which the debian-legal community almost universally rejects as
     non-free. By forcing any user or contributor—whether they live in
     New Zealand, Argentina, or Japan—to travel to Paris and navigate
     the French legal system to defend themselves, the license imposes
     an unreasonable, prohibitive burden. Debian considers this a
     restriction on the core freedoms to use, modify, and distribute
     the software (acting essentially as a fee or restriction,
     violating the spirit of DFSG #1: Free Redistribution).

     Discrimination Against Amateurs/Beginners (Preamble & Article 9.1)

     The Clause: The text states that the software's "use is reserved
     for developers and experienced professionals having in-depth computer
     knowledge."
     DFSG Conflict: This directly conflicts with DFSG #5: No Discrimination
     Against Persons or Groups. A free software license cannot say that a
     tool is only for experts, businesses, or researchers. If this text is
     interpreted legally as a usage restriction (rather than just a
     poorly-worded warranty disclaimer), it prevents students, amateurs,
     and beginners from exercising their right to use the software.

     The Obnoxious UI Advertising Requirement (Article 6.4)

     The Clause: The licensee must "ensure that use of the Software, its
     intellectual property notices and the fact that it is governed by the
     Agreement is indicated in a text that is easily accessible,
specifically
     from the interface of any Derivative Software."
     DFSG Conflict: This clause acts as an overly aggressive "advertising
     clause." While preserving copyright notices in source files is required
     and DFSG-compliant, forcing developers to alter the user interface of
     any derivative software restricts how developers can build and design
     their own tools. This conflicts with DFSG #3: Derived Works, which
requires
     that developers have the freedom to modify the software and create
     derivatives without arbitrary restrictions on how those derivatives
must
     function or be displayed (for example, if you make a headless, command-
     line, or embedded derivative, surfacing text in an "interface" is
     practically impossible).

     Over-Restrictive Notice Preservation (Article 6.4)

     The Clause: The licensee undertakes "to reproduce said notices, in an
     identical manner, in the copies of the Software modified or not".
     DFSG Conflict: While DFSG #4 allows licenses to require the integrity
     of the author's source code and copyright notices, demanding that
notices
     be preserved in an "identical manner" without allowing any format
     modifications can be a minor friction point for DFSG freeness. If a
Debian
     packager needs to convert documentation formats or refactor code
     structures, absolute identical reproduction of notice blocks can create
     technical/legal hurdles.

Kind regards

Mechtilde

Le 12/10/2026 à 18:16, Mechtilde Stehmann a écrit :

Hello Mechtilde,

Thanks for looking at licensecheck and for taking the time to report
this. However, I don't think there is an issue here: the CeCILL licenses
(v2 and later, including the CeCILL-B and CeCILL-C variants) are
considered free software licenses, and they are accepted in Debian main:

  * The FSF lists CeCILL as a free software license, compatible with
    the GNU GPL (article 5.3.4 explicitly allows relicensing under the
    GPL).
  * The OSI has approved CeCILL-2.1.
  * The ftp-masters have accepted CeCILL-licensed software in main for
    many years. For example, sollya itself (the origin of the
    "Sollya-4.1" exception found in this test file) and scotch are both
    distributed in main under CeCILL-C.

The concerns raised on debian-legal back in 2004-2005 were about CeCILL
v1. They were addressed in v2, notably by making the English version
authoritative and adding the GPL compatibility clause.

About the points you raised:

  * Choice of venue (article 13.2): such clauses do not restrict use,
    modification or redistribution, and they are not a fee in the
    sense of DFSG #1. Other licenses accepted in main contain similar
    clauses, for example MPL 1.1 (section 11) and CDDL (section 9).

  * "reserved for developers and experienced professionals": this
    sentence is part of the preamble's warning about the risks of using
    the software, as a justification for the absence of warranty. It is
    not an operative clause restricting who may use the software, so
    DFSG #5 is not affected.

  * Notice in the interface (article 6.4): "specifically" translates the
    French "notamment" ("in particular"), so the interface is given as
    an example, not as an exclusive requirement. This is comparable to
    the GPL-2 section 2(c) interactive notice or the GPL-3 "Appropriate
    Legal Notices"; software without an interface can meet it through
    its documentation. This is fine under DFSG #3.

  * Notices reproduced "in an identical manner": this is the usual
    requirement to keep copyright and license notices intact, as in
    the BSD licenses ("retain the above copyright notice"). DFSG #4
    explicitly allows it.

Finally, t/exception/Cecill/tv_implementpoly.reference is test data. It
exists precisely to check that licensecheck correctly detects this
license and its exception.

For these reasons I suggest to close this bug. If you think the status
of CeCILL in Debian should be reconsidered in general, the right place
to discuss it would be debian-legal or the ftp-masters, rather than a
bug against licensecheck.

Kind regards,
Xavier

Quoting Mechtilde Stehmann (2026-10-12 18:16:05)

I fail to see that licensecheck Contains any code licensed by CeCILL-C.

Specifically the file that you list above is not code.

 - Jonas

Hello Jonas,

Am 12.10.26 um 21:19 schrieb Jonas Smedegaard:

Please, tell us why this file is in the package. Why is it needed?
Thanks

Quoting Mechtilde Stehmann (2026-10-13 09:46:55)

Why do you ask?

I mean, even if the file was completely unused, or if it was baked into
executables included with binary packages, why is that a concern for
the DFSG team?

 - Jonas