Build process appears to trust its cache when it should not.

[srorso]

From Hercules issue #204:

A review of the provided logs suggests that at some point CMake had cached the fact that stdint/stdbool were not available at point and declined re-tests for their presence in subsequent builds. The issue in this case is while the answer is cached (no stdint), the process that led to that answer (the log from the run that generated the cached answer) is gone. And so not diagnosable.

Review how the cache is used and when it should be dumped.