Please port to Eigen 5.0

[merkys]

Eigen 5.0 has recently been released, and Debian and its derivatives are planning to switch to it soon. Please consider porting Supercell to Eigen 5.0, as currently it fails to build with the new version:

In file included from /build/reproducible-path/supercell-2.1.1+~0.0~git20221028.d8eeb73/src/core/cif_io.cpp:5:
/build/reproducible-path/supercell-2.1.1+~0.0~git20221028.d8eeb73/src/core/cif_io.h:10:10: fatal error: Eigen/Core: No such file or directory
   10 | #include <Eigen/Core>
      |          ^~~~~~~~~~~~
compilation terminated.
make[3]: *** [src/sc_cli/CMakeFiles/supercell.dir/build.make:82: src/sc_cli/CMakeFiles/supercell.dir/__/core/cif_io.cpp.o] Error 1
make[3]: *** Waiting for unfinished jobs....
In file included from /build/reproducible-path/supercell-2.1.1+~0.0~git20221028.d8eeb73/src/core/common_types.cpp:8:
/build/reproducible-path/supercell-2.1.1+~0.0~git20221028.d8eeb73/src/core/common_types.h:21:10: fatal error: Eigen/Core: No such file or directory
   21 | #include <Eigen/Core>
      |          ^~~~~~~~~~~~
compilation terminated.

[orex]

Thanks to Merkys for raising this issue — it was the last push I needed to finally update Supercell and bring it up to date with newer libraries versions.

Here’s the PR (#77) that will serve as the foundation for the next version of Supercell. There may still be a few small cosmetic changes, but overall this branch is going to become the base for the new release.

Regarding the Eigen 5.0 compilation issue you mentioned: on my side, the migration was completely straightforward and pretty much trivial. I wasn’t able to reproduce the error you showed.

You can check the GitHub Actions workflows section — I’m building and deploying Linux binaries there using the latest Eigen 5.x release, and everything works correctly.

So please try this branch on your side as well. If you run into any build-related issues, there’s still a chance to fix them before this gets merged into master and included in the release.

Best regards,
Kirill

[merkys]

Just checked your branch on Debian Unstable with system-provided Eigen 5.0.1 and Gemmi 0.7.5, build and tests pass successfully. Thanks a lot!