Package: xfce4-session Version: 4.12.1-5 Tags: fixed-upstream The Debian package of xfce4-session in stretch (and, apparently, in sid) is still affected by upstream bug #11698, for which a fix is available as upstream git commit 26f9ae8df629f02af0773df2ed82db6b85c5b556 .
Basically, xfce4-session always logs verbosely, even if XFSM_VERBOSE is not set in the environment.