David Hunt wrote,
| It appears to me that there are no useful functions gained from using a
| locallockfile on a nested block, although something unexpected might
| happen. 8-}
There is one exception: if the nested block launches a clone, a local lock-
file on the recipe that opens the block (and spawns the clone) is meaningful:
the parent procmail will not spawn the clone until it can get the lock. Thus
if two or more incoming messages both trigger clones, a local lockfile there
can make the clones run serially. If you also use the `w' or `W' flag, the
parent will hold onto the lockfile until the clone exits. The effect is sim-
ilar to a global lockfile for the clones (except that the parents, not the
clones, handle the locking and waiting).