forkM_maybe doc thing_inside
= do { unsafeInterleaveM $
do { traceIf (text "Starting fork {" <+> doc)
- ; mb_res <- tryM thing_inside ;
- case mb_res of
+ ; mb_res <- tryM $
+ updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
+ thing_inside
+ ; case mb_res of
Right r -> do { traceIf (text "} ending fork" <+> doc)
; return (Just r) }
Left exn -> do {