When run on the attached file, z3 outputs a result after a few seconds, coherent with the rlimit. But then it keeps running (with high CPU consumption) for a long time.

That extra running time seems to grow as the rlmit gets higher.

$ z3  keeps_running.smt rlimit=60000000
unknown
(:reason-unknown "canceled")
(:rlimit 60007344)                     <---------takes 31 s
$                                      <---------takes another ~30 s of high CPU usage

Bug present in current HEAD 374609b but also in previous versions (4.12.1, 4.8.17)
keeps_running.smt.zip