The compiler's support about to be set up wrong (8)
I believe the answer is:
improper
'wrong' is the definition.
(synonyms)
'the compiler's support about to be set up' is the wordplay.
'the compiler's' becomes 'im' (I've seen this in other clues).
'support' becomes 'prop' (prop is a kind of support).
'about to' becomes 're' (I can't justify this - if you can you should believe this answer much more).
'be set up' says the letters should be written in reverse.
're' written backwards gives 'er'.
'im'+'prop'+'er'='IMPROPER'
Can you help me to learn more?
(Other definitions for improper that I've seen before include "Unfitting, out of place" , "vulgar" , "unacceptable?" , "Hardly meet" , "Unseemly; (fraction) more than one" .)