data.table license compatibility

[PhilippeSantenoise]

The exhibit B of the MPL license makes code incompatible with the secondary licenses. This issue has already discussed (#2456 (comment)), but the response is not clear for me.
Several R packages with a secondary license (example: Ac3net, AF, ...) depend on the data.table R package and I cannot find any details on this part.
Is a code with a secondary license (as GPL) still compatible with data.table license ?

[mattdowle]

Thank you for linking to the response there. Which part of that detailed response is not clear? If anyone reading this can translate the nuances to French, perhaps that will help?

At the risk of adding more here away from the main in-one-place PR, this seems like a simple misunderstanding, so I'll put it into context of your question. If Ac3net and AF use data.table as a library then their license doesn't matter to data.table. Nothing seems unusual about Ac3net and AF on first glance, so I'm not sure why you've singled them out: just because they are the first 2 alphabetically of 1,065 packages on CRAN that use data.table? I would guess that most of those are GPL, just as Ac3net and AF. However, instead of using data.table as library, if they have taken data.table C code out of data.table and included it in their package, likely modified, then those parts need to be licensed under MPL. For example, the collapse package does that.

Please close this issue if everything is clear now.

[PhilippeSantenoise]

Thank you for your quick reply.
All is clear now.