To reproduce on a 64-bit system: 1. Add a TEST_ASSERT(false) to any API test (e.g., WebKit2/WKString) 2. set-webkit-configuration --32-bit 3. build-webkit 4. run-api-tests run-api-tests says that the test passed, even though it did not.
I think this is because run-api-tests runs TestWebKitAPI via the arch utility in this case, and arch isn't propagating TestWebKitAPI's return code.
<rdar://problem/9068438>