If one tries to 'show node <some_node>' in vppctl and typos the name, vpp crashes after a moment, then vppctl quits too.

For some reason, vpp has difficulty formatting the "unknown node name" error message.  I think it is allocating memory until it runs out.  Here is a backtrace while that is happening:

vppctl# show node all

#0 0x00007ffff63d52c0 in mspace_usable_size_with_delta (p=p@entry=0x7ffa75c495\
24)
at /usr/src/debug/vpp-19.01/src/vppinfra/dlmalloc.c:4326
#1 0x00007ffff636f5e8 in clib_mem_size (p=<optimized out>)
at /usr/src/debug/vpp-19.01/src/vppinfra/mem.h:250
#2 _vec_resize_inline (data_align=<optimized out>, header_bytes=<optimized out\
>,
data_bytes=<optimized out>, length_increment=<optimized out>, v=<optimized \
out>)
at /usr/src/debug/vpp-19.01/src/vppinfra/vec.h:139
#3 va_format (s=0x7ffa75c4952c "unknown node name: 'all", s@entry=0x0,
fmt=fmt@entry=0x7ffff6cb8f07 "unknown node name: '%U'", va=va@entry=0x7fffb\
4ec7b58)
at /usr/src/debug/vpp-19.01/src/vppinfra/format.c:413
#4 0x00007ffff636affa in _clib_error_return (errors=<optimized out>, errors@en\
try=0x0,
code=code@entry=0, flags=flags@entry=0,
where=where@entry=0x7ffff6cb8da0 <_FUNCTION_.39614> "show_node",
fmt=fmt@entry=0x7ffff6cb8f07 "unknown node name: '%U'")
at /usr/src/debug/vpp-19.01/src/vppinfra/error.c:163
#5 0x00007ffff6c902d5 in show_node (vm=0x7ffff6ec8300 <vlib_global_main>, inpu\
t=<optimized out>,
cmd=<optimized out>) at /usr/src/debug/vpp-19.01/src/vlib/node_cli.c:497