I don't see anything wrong in what you are doing.  I tried to reproduce this
bug on rev 69141 using the second method (the one submitted on June 6) with
the files attached to the report but it did not crash.  However, if I
use the attached ecrc60_new instead of the original ecrc60 previously attached
(and with all the *.wb files the same as the ones originally attached), then
it crashes every time.

Please try method 2 (added on June 6) but copy ecrc60_new into ~/.es/ecrc60
instead of the originally submitted ecrc60 file.
Hopefully, you can then reproduce it (crashes every time for me).

Output of isainfo -kv for me is "64-bit amd64 kernel modules", just in case
it is relevant.