Comment 1 for bug 2035644

Looks like third-party packages are involved, so details on where to find them would be good.

I presume the formatting of the data is different in dpkg/status vs. the Packages file in the repo as libapt does string comparisons rather than very costly fully parsed, transformed & cleaned comparisons and whatever tool is used to create the Packages file might or might not do the same transformations dpkg does. apt-ftparchive for example mostly doesn't.

dpkg e.g. has the tendency to remove 0-epochs from version numbers which might be included in a dependency. Wild guess only – we would need the actual data to know.