Various job lots seen to incorporate constant warning (6,6)
I believe the answer is:
Here is my best explanation:
'warning' is the definition.
(object lesson is a kind of warning)
'various job lots seen to incorporate constant' is the subsidiary indication.
'various' is an anagram indicator.
'to incorporate' indicates putting letters inside.
'constant' becomes 'c' (mathematical abbreviation).
'joblotsseen' is an anagram of 'objetlesson'.
'objetlesson' going around 'c' is 'objectlesson'.
(Other definitions for object lesson that I've seen before include "What may be striking", "Example typifying a principle", "Instructive experience", "punishment intended as a warning to others?" and "shows what one should do".)