How to get the corresponding taskName with a build cachekey

There’s no way to do this, for two main reasons:

1. A cache key is effectively a hash, meaning from the inputs I can reproduce the same hash, but you can’t infer the inputs from the hash. It’s a one way algorithm.
2. Even if you could deduce the cache inputs from the hash, you wouldn’t in this case because task name is not part of the hash. That is, two tasks with different names, for otherwise the same inputs, can produce the same cache key.