Bugpoint's current documentation does specify that the result of a run is stored as the current design,
however it's easy to skim over what that means in practice.
Add a documentation comment to explain specifically that an after bugpoint `write_xyz` pass is required to save
the reduced design.
log("and the same script, repeating these steps while it can find a smaller design that\n");
log("still causes a crash. Once this command finishes, it replaces the current design\n");
log("with the smallest testcase it was able to produce.\n");
+ log("In order to save the reduced testcase you must write this out to a file with\n");
+ log("another command after `bugpoint` like `write_rtlil` or `write_verilog`.\n");
log("\n");
log(" -script <filename> | -command \"<command>\"\n");
log(" use this script file or command to crash Yosys. required.\n");