The tests and documentation have been using the core storage layer but soon that will depend entirely on the C library, creating a bootstrap problem (i.e. the storage layer will be needed to build the C library).
Create a simplified Posix storage layer to be used by documentation and the parts of the test code that build and execute the actual tests. The actual tests will still use the core storage driver so they can interact with any type of storage.
Code generation saved files even when they had not changed, which often caused code generation cascades. So, don't save files unless they have changed.
Use rsync to determine which files have changed since the last test run. The manifest of changed files is saved and not removed until all code generation and builds have completed. If an error occurs the work will be redone on the next run.
The eventual goal is to do all the builds from the test/repo directory created by rsync but for now it is only used to track changes.
