Closed
Description
We now have incremental mode but it's off by default; we would like to turn it on by default.
This is a follow-up on #932, which was closed after #1292 landed.
Dependencies are at least #1349 (add tests), #1350 (check which files we rechecked), and #1351 (interaction between -i and -s).
We probably also want some command-line options to force resetting the cache or control the name of the cache directory.