In Memory Cache

Buck2 can maintain an in-memory cache of actions it executed. This allows actions to skip re-running even when they are (transitively) affected by file changes.

Enabling the in-memory cache

This feature requires enabling Deferred Materialization first. This is necessary so that Buck2 knows what's on disk. This requirement might go away once we decouple keeping track of what's on disk and deferred materialization.

Once done, to enable, add this to your Buckconfig:

[buck2]
hash_all_commands = true