Still python exception. about gef HOT 7 CLOSED

$ gdb -q dwarfdump
gef loaded, `gef help' to start, `gef config' to configure
35 commands loaded (17 sub-commands), using Python engine 2.7
Reading symbols from dwarfdump...done.
gef> b putchar
Breakpoint 1 at 0x401770
gef> r /bin/ps
Starting program: ..../dwarfdump /bin/ps
....
Breakpoint 1, putchar (c=c@entry=10) at putchar.c:26
26      putchar.c: No such file or directory.
gef> heap arenas 
[+] Listing active arena(s):
Python Exception <class 'gdb.error'> Cannot convert value to int.: 
Error occurred in Python command: Cannot convert value to int.
gef> heap bins
Python Exception <class 'gdb.error'> Cannot convert value to int.: 
Python Exception <class 'gdb.error'> Error occurred in Python command: Cannot convert value to int.: 
Error occurred in Python command: Error occurred in Python command: Cannot convert value to int.