{"bits":64,"error":
write-json: expected argument of type ; given: '(("start" 59.8 61.4 57.3 60.9 60.8 57.2 0.0 0.0 59.5 0.0 0.0 61.1 0.0 61.9 60.5 61.1 0.0 59.2 8.0 60.0 0.0 0.0 0.0 61.7 0.0 58.1 62.0 0.0 61.8 0.0 57.8 0.0 0.0 61.7 0.0 57.2 62.0 0.0 0.0 0.0 60.8 0.0 59.7 0.0 60.8 0.0 0.0 61.6 0.0 60.7 59.2 61.2 0.0 56...
  context...:
   /usr/local/racket/collects/json/main.rkt:156:2: write-jsval
   /usr/local/racket/collects/json/main.rkt:100:0: write-json*
   /home/nightlies/herbie/report-cost-multi-alts/src/web/thread-pool.rkt:13:0: run-test
   .../racket/place.rkt:41:31: main