Developing a barren site may be a tricky problem (5-6)
I believe the answer is:
brain-teaser
'a tricky problem' is the definition.
(I've seen this before)
'developing a barren site' is the wordplay.
'developing' is an anagram indicator (letters developed into a new form).
'a'+'barren'+'site'='abarrensite'
'abarrensite' with letters rearranged gives 'BRAIN-TEASER'.
'may be' is the link.
(Other definitions for brain-teaser that I've seen before include "Poser" , "Difficult puzzle" , "Riddle" , "Puzzle requiring thought" , "Problem, puzzle" .)