Calculix nixos package ^1 is a Finite Element library. There are 2 applications it is distributed with: ccx ^2 (aka 'CrunchiX') and cgx ^3 (aka 'GraphiX')
Per the package info in nixpkgs we can see that the calculix packaged is ccx_$version.src.tar.bz2
Issue description
Calculix nixos package ^1 is a Finite Element library. There are 2 applications it is distributed with: ccx ^2 (aka 'CrunchiX') and cgx ^3 (aka 'GraphiX')
Per the package info in nixpkgs we can see that the calculix packaged is
ccx_$version.src.tar.bz2
https://github.com/NixOS/nixpkgs/blob/aef7c94e241b5ed09413fdc4a26eb12337b192db/pkgs/applications/science/math/calculix/default.nix#L9-L12
In repology we can see there are 2 different packages https://repology.org/project/calculix-ccx & https://repology.org/project/calculix-cgx
Therefore, I recommend renaming the nixos 'calculix' package to 'calculix-ccx'