This compiler's transparent keeping yours truly keen (9)
I believe the answer is:
impatient
'keen' is the definition.
(thesaurus)
'this compiler's transparent keeping yours truly' is the wordplay.
'this compiler's' becomes 'im' (I've seen this in other clues).
'transparent' becomes 'patent' (I've seen this before**).
'keeping' indicates putting letters inside.
'yours truly' becomes 'i'.
'patent' enclosing 'i' is 'patient'.
'im'+'patient'='IMPATIENT'
(Other definitions for impatient that I've seen before include "Fidgety" , "appeared anxious" , "dying" , "Restless or short-tempered" , "Restlessly eager" .)