In 60445, browse the implementors of #cacheAt:for:ifAbsentPut:
and the view the Versions of each.��
Curiously some of them have a blank user/date.

There are others...
�� �� errors := OrderedCollection new.
�� �� versions := (CompiledMethod allInstances) flatCollect: [:cm|��
[VersionBrowser new setRGMethodFrom: cm asRingDefinition; buildChangeList]��
on: Error do:[:ex| errors add: (cm -> ex). #()] ].
�� �� versions size.��
"112131"
�� �� emptyStamps := versions select: [:rgm| rgm stamp = ''].
�� �� emptyStamps size.��
"9264"
or 8%

Maybe some are historic, but I'd guess this one at least is not so old...��
GLMFastListDataSource>>cacheAt:for:ifAbsentPut:

What reasonable action do we need to take?

cheers -ben