Eli Zaretskii <eliz@gnu.org> writes:

> Did you try loading it as a .el file?

Yes, but I couldn't reproduce the bug.

>> The Lisp backtrace is really short:
>> 
>> Thread 7 (Thread 0x7f1cd4dec700 (LWP 21837)):
>> "erb--benchmark-monitor-func" (0x158ec58)
>
> If you succeed in reproducing this when this code is loaded
> uncompiled, the backtrace might be more helpful.

The assertion happens in the Bswitch case of exec_byte_code when it's
running erb--benchmark-monitor-func, and there's only one 'switch' in
the disassembled bytecode, see line 16: