Like much of this crossword it did nothing for me. At the very least the clue needs the word 'when' to be inserted and the order of the first two words to be reversed, ie 'Primarily evil when occurring in Lent?'. If you interpret 'primarily' as meaning 'fundamentally' in the definition (which is the whole clue), this just about works. As the clue stands it suggests that feasts are a bad thing and largely occur in Lent.
Yes indeed, the wordplay is E ('Evil, primarily') 'occurring in' FAST ('Lent?'), but it is intended to be an &lit, with the definition being the whole clue (otherwise there is no definition). I don't think a feast could reasonably be described '[an] evil primarily occurring in Lent?', but one could perhaps be termed 'primarily evil when occurring in Lent?'
...sorry mamyalynne - I missed the first part of the thread. I agree that the clue is fine as it is (as long as the '?' is there).
Sorry, Spoffy - but you're probably right.
Well, for what it's worth, I agree with Mamya. The clue works ok as an &lit - if someone believes strongly that Lent is a fast, then a feast might be seen as evil.
Let's be honest - if I had seen this clue in a Guardian puzzle I would have kept my electronic mouth shut. But this is a barred puzzle where clueing accuracy is (or at least used to be) highly valued. Feasts don't primarily occur in Lent, and 'primarily' is a prepositive adverb so it can't be modifying the adjective 'evil' (compare 'A feast is particularly evil during Lent' with 'A feast is evil particularly during Lent'); it would have to be written as 'Primarily evil' to achieve that purpose.
I find it frustrating that this idea could easily have been realised in a way that actually led to the answer, eg "What's close to sacrilege when held in Lent?"