This compiler succeeded twice, creating difficulty (4)
I believe the answer is:
mess
'difficulty' is the definition.
(mess is a kind of difficulty)
'this compiler succeeded twice' is the wordplay.
'this compiler' becomes 'me' (the person who is writing these clues).
'succeeded' becomes 's' (genealogical abbreviation).
'twice' indicates the doubling of some letters.
's' duplicated is 'ss'.
'me'+'ss'='MESS'
'creating' is the link.
(Other definitions for mess that I've seen before include "State of confusion or untidiness" , "An officer's untidy dining room" , "Where those who serve eat" , "Canteen - chaos" , "Canteen - muddle" .)