Gdb "osv info threads" doesn't work on Fedora 34

[nyh]

On Fedora 34 (gcc 11.2.1), the gdb command "osv info threads" doesn't work:

(gdb) osv info threads
  id  address             name            cpu  status         vruntime  total_cpu_time location
Traceback (most recent call last):
  File "/home/nyh/osv.tmp2/osv/scripts/loader.py", line 1034, in invoke
    cpu = thread_cpu(t)
  File "/home/nyh/osv.tmp2/osv/scripts/loader.py", line 1010, in thread_cpu
    return d['_cpu']
gdb.error: There is no member or method named _cpu.
Error occurred in Python: There is no member or method named _cpu.