bug#47106: Bubblewrap hates Guix containers 😞

[Leo Prikler <leo.prikler@student.tugraz.at>]

Am Samstag, den 13.03.2021, 13:27 +0100 schrieb Bengt Richter:
> Hi,
> 
> On +2021-03-13 12:07:51 +0100, Leo Prikler wrote:
> > Hi!
> > Am Samstag, den 13.03.2021, 11:48 +0100 schrieb Ludovic Courtès:
> > > Hi!
> > > 
> > > Leo Prikler <leo.prikler@student.tugraz.at> skribis:
> > > 
> > > > both Epiphany and Eolie (post fixing #47097; will submit patch
> > > > shortly)
> > > > fail inside Guix containers with the suggested
> > > > incantation.  After
> > > > getting the environment to no longer complain about $DISPLAY by
> > > > adding
> > > > `--preserve="XAUTHORITY" --expose=$XAUTHORITY', it repeatedly
> > > > outputsn
> > > > lines like
> > > > bwrap: Can't find source path /sys/class: No such file or
> > > > directory
> > > > before closing the process altogether.
> > > 
> > > What is ‘bwrap’ looking for?  /sys is mounted inside ‘guix
> > > environment -C’,
> > > but perhaps it needs something special?
> > > 
> > > I suggest running these things (or ‘bwrap’ directly) in ‘strace
> > > -f -o
> > > log’ inside the container to see.
> > It seems to be 
> > > openat(AT_FDCWD, "/sys/class/dmi/id/chassis_type", O_RDONLY) = -1
> > > ENOENT (No such file or directory)
> > > openat(AT_FDCWD, "/sys/firmware/acpi/pm_profile", O_RDONLY) = -1
> > > ENOENT (No such file or directory)
> > 
> > I haven't repeated that for all warnings of similar kind, but if I
> > add
> > `--expose=/sys/block --expose=/sys/class --expose=/sys/bus --
> > expose=/sys/dev --expose=/sys/devices` to the invocation, I instead
> > get
> > a warning, that the WebKitWebProcess can't open $DISPLAY.  I'm not
> > sure
> > how to resolve that one, given that I already had to sneak DISPLAY
> > and
> > XAUTHORITY into the container, but it's a start.
> > 
> > Regards,
> > Leo
> > 
> Does $DISPLAY mean ":0" and does the Wayland server answer that with
> its XWayland X-interface?
In my setup $DISPLAY=:1, but obviously the exact value depends on other
circumstances (i.e. if there's already an open session belonging to
another user it'd be :2, :3, ...).  I'm not sure how X vs. Wayland
plays out here, but I'm still using Gnome on X, so that should
hopefully not be an issue here.

> I am wonderering how that is resolved inside a container.
Well, for X you'd usually preserve DISPLAY and XAUTHORITY and also
expose $XAUTHORITY or something along those lines.  Not sure how you
Wayland folk do that.

Regards,
Leo