The JetStream2 and JetStream3 harnesses currently report results using `fetch`. Because the header is manually constructed, and there is a typo in both harnesses ("headers" -> "heeaders"). JS2: https://github.com/WebKit/WebKit/blob/ec6f02c2f3242338888639458e4b258cda0e4b77/PerformanceTests/JetStream2/JetStreamDriver.js#L514 JS3: https://github.com/WebKit/WebKit/blob/ec6f02c2f3242338888639458e4b258cda0e4b77/PerformanceTests/JetStream3/JetStreamDriver.js#L514 This isn't an issue at the moment, since somehow the twistd server that run-benchmarks is using is able to work around the typo, but if we ever switch to a different HTTP server implementation (https://bugs.webkit.org/show_bug.cgi?id=259835), this will probably come back to bite us. We should fix this - or even better, switch to using XHR like we patch Speedometer and MotionMark to do: https://github.com/WebKit/WebKit/blob/ec6f02c2f3242338888639458e4b258cda0e4b77/Tools/Scripts/webkitpy/benchmark_runner/data/patches/webserver/Speedometer2.patch#L60
<rdar://problem/114116489>