Dead loop, service cannot be created

[lys861205]

branche of master
at src/core/lib/debug/trace.cc:57
for (t = root_tracer_; t; t = t->next_tracer_) { if (0 == strcmp(name, t->name_)) { t->set_enabled(enabled); found = true; } }
don`t quit for loop,

print the 't' value

connectivity_state, 0x7f2db6f0c520
bdp_estimator, 0x7f2db6f0c500
server_channel, 0x7f2db6f0c4e0
queue_pluck, 0x7f2db6f0c4c0
op_failure, 0x7f2db6f0c410
compression, 0x7f2db6f0c3f0
call_error, 0x7f2db6f0c3d0
api, 0x7f2db6f0aaa0
timer_check, 0x7f2db6f0aa80
timer, 0x7f2db6f0a9f0
resource_quota, 0x7f2db6f0a8b0
executor, 0x7f2db6f0a210
tcp, 0x7f2db6f0a1f0
http1, 0x7f2db6f0a1b0
handshaker, 0x7f2db6f0a190
channel, 0x7f2db6f0a170
subchannel_pool, 0x7f2db6f0a150
subchannel, 0x7f2db6f0a0b0
health_check_client, 0x7f2db6f0a090
client_channel_routing, 0x7f2db6f0a070
client_channel_call, 0x7f2db6922a70
client_idle_filter, 0x7f2db6922a50
cares_resolver, 0x7f2db6922a30
cares_address_sorting, 0x7f2db6922a00
round_robin, 0x7f2db69229e0
pick_first, 0x7f2db69229c0
xds, 0x7f2db69229a0
xds_client, 0x7f2db6922980
cds_lb, 0x7f2db6922960
glb, 0x7f2db6922890
inproc, 0x7f2db6f0a170
subchannel_pool, 0x7f2db6f0a150
subchannel, 0x7f2db6f0a0b0
health_check_client, 0x7f2db6f0a090
client_channel_routing, 0x7f2db6f0a070
client_channel_call, 0x7f2db6922a70
client_idle_filter, 0x7f2db6922a50
cares_resolver, 0x7f2db6922a30
cares_address_sorting, 0x7f2db6922a00

code link
trace.cc

[karthikravis]

What is the test case for this @lys861205 ?