[arch-general] .xsession-errors - can't startx with that file

[Dutch Ingraham]

On Sun, Sep 18, 2016 at 09:23:01AM -0500, Doug Newgard wrote:
> On Sun, 18 Sep 2016 09:11:45 -0500
> Dutch Ingraham <stoa at gmx.us> wrote:
> 
> > Hello all:
> > 
> > TL;DR: One Arch installation will allow redirecting startx's stderr to
> > a file, one won't.  What is the difference between systems?
> > 
> 
> Is X running as root or as the user (rootless)? This can change based on
> configuration and on drivers used.

Excellent question - how is this conclusively determined?  Note I have taken no
explicit action either way, i.e., to enable rootlessness or not.

Looking at the xorg wiki, it appears as though 3 conditions are necessary for
running "rootless":

1. systemd >= 216; OK, I'm at 231 on both machines;
2. start X via xinit; OK, I'm using xinit through startx, not a display manager;
3. if I can summarize, if using a proprietary display driver, such as Catalyst
or Nvidia, need to take an extra step to run rootless; *this may be the issue.*

On the machine where redirection works, I am using the nvidia proprietary
driver; on the machine where the error occurs, I am using the xf-video-ati
driver.

So, unless I have step 3 above backwards (which is entirely possible), the
question is how to redirect stderr when running rootless? (If I am in fact
misunderstanding, please explain so a moron like me can understand!)

Thanks for your help.