Investigation
When running a passthrough suite with the logical session cache refresh set to 100ms, it can cause failures in list_local_sessions.js. The test expects a session to exist, but it's likely been reaped by the time that assert.expect is run.
Proposed Fix
After some thought, it seems the best idea to blacklist list_sessions.js and list_all_sessions from the logical session cache suites. These tests rely on the command `refreshLogicalSessionCacheNow`, which is supposed to refresh the cache in a deterministic fashion. Running these tests with the background refresh thread on interferes with the deterministic nature of the tests, because refresh operations can happen when they're not supposed to.
Since both these tests are in jsCore, I'm not worried about losing test coverage.