xsession-errors bloated humongous [Solved]

[l0dr3]

configuring errors to go to /tmp
and
USB port is erratic
solved issue

Glad your issue is solved ...

in my case ...

I'll do some further test and enable xfwm-compositor temporarily, to see if the flooding starts again, what then would IMO indicating a problem in/with X11/Mesa
and/or the graphics driver
and/or the TigerVNC capture driver

... indeed compton compositor was the culprit - in the combination of

a user-defined background wallpaper ++ Intel IRIS GPU vaapi-enabled driver ++ tigervnc x11-capture-library ++ latest v6.6 series kernel ...

my .xsession-errors is flooded with ~10lines/second (~400MB/day).

Disabling compton Session-Autostart and using xfwm-compositor with 'VBlank' disabled (this is necessary for tigervnc capture driver!), solved it for me finally (thus far )

[Charlie Brown]

...
redirect ~/.xsession-errors to /tmp/...

... start anew with each boot ...

Good idea, so that it could be ootb. I did both though no problems here :)