libcifpp's Chemical Component Dictionary

[multimeric]

It has been brought to my attention that the current libcifpp package doesn't currently include the Chemical Component Dictionary. I believe libcifpp looks in $PREFIX/share/libcifpp for the dictionary.

On the one hand, there possibly is some argument for allowing the dictionary to be updated separately from the library itself, and indeed upstream provides a mechanism for automatically updating the dictionary each week. On the other hand, it doesn't feel correct for a package to update itself in this way, in which case we should set CIFPP_DOWNLOAD_CCD=ON so that it gets bundled with the package. I will probably put in a PR to this effect soon, but I welcome feedback.

As an aside, I think the current workaround is just to manually download it with: wget https://files.wwpdb.org/pub/pdb/data/monomers/components.cif --directory-prefix $CONDA_PREFIX/share/libcifpp. Disclaimer: I haven't tested this.

[clebreto]

Hi Michael,

Thanks for pointing the problem of the dictionary frequent update.

In such case, I would advocate for a separate conda package for the dictionary, that could be updated automatically upon update of the cif file.
This package would be a dependence of the libcifpp package.

Conda packages, as far as I am concerned, should be self contained. They are meant to simplify ones usage of a given library.

Another (ugly) option would be to trigger the download at installation of the package.