This compiler's rubbish, being naughty! (6)
I believe the answer is:
impish
'naughty' is the definition.
(I've seen this before)
'this compiler's rubbish' is the wordplay.
'this compiler's' becomes 'I'm' ('I'm', referring to the crossword compiler).
'rubbish' becomes 'pish' (I've seen this before).
'im'+'pish'='IMPISH'
'being' is the link.
(Other definitions for impish that I've seen before include "troublesome" , "Teasingly mischievous" , "saucy" , "Wicked" , "Playful" .)