print doesn't work when debugging code in nginx

[Aliaksandr Rahalevich]

from standalone console:

$ make repl 
[1] ngx(timer)> print(123)
123
=> true

but when debugging nginx:

# nginx -c /tmp/ngx.conf 
... log messages here ...
[1] ngx(content)> print(123)
2016/09/23 12:52:05 [notice] 155#0: *1 [lua] [C]:-1: 123, client: 172.17.0.1, server: , request: "GET / HTTP/1.1", host: "172.17.0.2:8080"
=> nil
[2] ngx(content)> 

print output appears in logs.
Would be nice if print can always print as expected.