Yes that's exactly how it works in serialized build/mode. Are you sure not ultimately compiling with -DSQLITE_THREADSAFE=0 or 2? Also the serialized setting is

Yes that's exactly how it works in serialized build/mode. Are you sure not ultimately compiling with -DSQLITE_THREADSAFE=0 or 2? Also the serialized setting is distinct from the isolation level. sqlite has a famously extensive test suite and is effectively one of the most heavily tested libraries ever, and there are multithread tests in the suite. If your tests are triggering some other kind of race/undefined behavior there is also that to consider.