[Debichem-devel] Bug#1136310: openbabel: FTBFS with libeigen3-dev 5.0 (major version transition)

[Anton Gladky]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Package: src:openbabel
Version: 3.1.1+dfsg-14
Severity: important
Tags: sid forky ftbfs
User: debian-devel at lists.debian.org
Usertags: eigen3-5.0

Dear Maintainer,

your package depends on libeigen3-dev. The upstream released a
new major version of this mathematical library, 5.0.0. Some
basic information about new features and changes in this version
can be found here:

  https://libeigen.gitlab.io/releases/5.0/

This is a major version change and may require code changes in packages
depending on eigen3. The key breaking changes include:

  - Minimum required C++ standard is now C++14
  - Changes in the build system integration
  - Some API name changes

openbabel FTBFS with libeigen3-dev 5.0.1. The full build log is available at:

  https://debusine.debian.net/debian/developers-gladk-eigen3/artifact/3759397/

Here is the most probably relevant part of the failing build log:
    ===========================================

- -- Detecting CXX compile features - done
- -- Eigen version .. found in /usr/include/eigen3, but at least version 2.91.0 is required
CMake Error at /usr/share/cmake-4.3/Modules/FindPackageHandleStandardArgs.cmake:290 (message):
  Could NOT find Eigen (missing: EIGEN_VERSION_OK) (Required is at least
  version "2.91.0")
Call Stack (most recent call first):
  /usr/share/cmake-4.3/Modules/FindPackageHandleStandardArgs.cmake:654 (_FPHSA_FAILURE_MESSAGE)
  modules/FindEigen.cmake:76 (find_package_handle_standard_args)
  CMakeLists.txt:49 (find_package)


- -- Configuring incomplete, errors occurred!
	cd .pybuild/cpython3_3.14/build && tail -v -n \+0 CMakeCache.txt
==> CMakeCache.txt <==
# This is the CMakeCache file.
# For build in directory: /build/reproducible-path/opengv-1.0+1git91f4b1/.pybuild/cpython3_3.14/build
# It was generated by CMake: /usr/bin/cmake
# You can edit this file to change values found and used by cmake.
# If you do not want to change any of the values, simply exit the editor.
# If you do want to change a value, simply edit, save, and exit the editor.
# The syntax for the file is as follows:
# KEY:TYPE=VALUE
# KEY is the name of a variable in the cache.
# TYPE is a hint to GUIs for the type of VALUE, DO NOT EDIT TYPE!.
# VALUE is the current value for the KEY.

    ===========================================
libeigen3-dev_5.0.1-1 is available in experimental.

When this package version lands into unstable (probably at the beginning
of June 2026), this bug will be increased in severity to serious.

Thanks,

Anton
-----BEGIN PGP SIGNATURE-----
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=4grn
-----END PGP SIGNATURE-----