Messiah 's difficult passage or solo a diva botched (3,8)
I believe the answer is:
via dolorosa
'messiah 's difficult passage' is the definition.
(term for the path Jesus took to crucifixion)
'or solo a diva botched' is the wordplay.
'botched' indicates an anagram.
'or'+'solo'+'a'+'diva'='orsoloadiva'
'orsoloadiva' is an anagram of 'VIA DOLOROSA'.
(Other definitions for via dolorosa that I've seen before include "Way to Crucifixion" , "Christ's route to Calvary" , "Distressing way" , "Pilgrim's passage" , "The way to Calvary" .)