Reid-E
commented
5 years ago This is an API issue, not a library issue. The library just requests a booster from the API using the sets/:id/booster endpoint.
This is old, but if it hasn't been addressed yet, and you're still concerned with it, you should submit this concern in the API repository.
Generating an Eldritch Moon booster with generate_booster occasionally results in a booster that contains one of the "Meld" cards; "Brisela, Voice of Nightmares", "Hanweir, the Writhing Township" and "Chittering Host" (I have only confirmed this with Brisela). These cards are entities created by the use of the Meld ability to combine two other cards; hence they do not physically exist as cards and the game rules prevent them from existing in virtual formats in any other context than gameplay.
It would be nice if the command were prevented (or able to be prevented) from including in generated boosters from more recent expansions cards that are considered by Gatherer to be part of that expansion but do not exist in the box/booster paradigm (such as Buy-A-Box promotional cards and cards included only in the introductory Planeswalker Decks) but boosters that include cards that do not exist at all at least is incorrect behaviour.