Please, no. My experience with the scons build cache is that it exists solely to introduce mysterious compile failures when the cache is out of sync. Eventually you get so distrustful of it that you end up just blowing away the cache as a matter of course.
That usually means your build graph and target signatures are incomplete and you need to figure out where you have a dependency that you haven’t told SCons about.
Exactly. Another way to say this is that if you have an incomplete build graph or target signatures, you will find out from your mysteriously corrupt build output.
It's a pretty old idea, going back to "derived objects" in ClearCase aka wink-ins.
If you think about it though, it's not hard to cons up a tool that files objects on disk by normalizing all the inputs to a compile step, and retrieving that object if it exists. Here's one but there's others.
my experience is that it will end up corrupted and bringing lots of ignote errors no one could have explained, and finally disappear by removing all precompiled files, chaces and databases.