Swiften and glib warnings go straight to terminal which launched the service

Having started a service weeks ago from a tmux shell on my server, now I have that shell's scrollback full of such entries

(process:6411): Json-CRITICAL **: json_node_get_object: assertion 'JSON_NODE_IS_VALID (node)' failed

[warning] Swiften/Component/ComponentSessionStanzaChannel.cpp:50 send: Component: Trying to send a stanza while disconnected.

Setup: Gentoo Linux, spectrum-2.0.9, swift-4.0.2. I launch spectrum through OpenRC init script which invokes spectrum2_manager. Logging configs:

decent /etc/spectrum2 # grep -F -A 5 '[logging]' transports/skype.cfg
[logging]
# log4cxx/log4j logging configuration file in ini format used for main spectrum2 instance.
config = /etc/spectrum2/logging.cfg

# log4cxx/log4j logging configuration file in ini format used for backends.
backend_config = /etc/spectrum2/backend-logging.cfg
decent /etc/spectrum2 # head -n999 logging.cfg backend-logging.cfg
==> logging.cfg <==
log4j.rootLogger=debug, R

log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=/var/log/spectrum2/${jid}/spectrum2.log

log4j.appender.R.MaxFileSize=10000KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1

log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%d %-5p %c: %m%n

# Disable XML category
log4j.category.Component.XML = OFF

==> backend-logging.cfg <==
log4j.rootLogger=debug, R

log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=/var/log/spectrum2/${jid}/backends/backend-${id}.log

log4j.appender.R.MaxFileSize=10000KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1

log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=${pid}: %d %-5p %c: %m%n
decent /etc/spectrum2 #

SpectrumIM / spectrum2

Swiften and glib warnings go straight to terminal which launched the service #321