Simple repro: xlsfonts should show more than 4 usable fonts.

it would be even better if we could make it support fontconfig ...

or have our startup logic use fontconfig to enumerate paths and pass them to xwayland ...

You mean have Xwayland support fontconfig? Seems like that would be ideal, but X11 doesn't appear to do anything smart here: https://wiki.archlinux.org/index.php/font_configuration#Font_paths

Since this is just for X11's font handling, I was going to pass in the path manually (-fp /usr/share/fonts/X11) in our Xwayland command line.

i'm trying to avoid encoding distro-specific policies into our daemons.  what works in the current Debian container is not necessarily the right answer for all containers and even package configurations.  if we could enumerate the paths on the fly via fontconfig we'd be able to adapt to dynamically based on the system/configuration.

FcConfigGetFontDirs would enumerate the paths. But it does add another dependency to sommelier/termina.

Xwayland ignores all conf files, so no specifying font dirs there. Also, no other Wayland compositor that I've seen bothers specifying the font path. They just use the path built-in at compile time by the distro packaging.

I agree we shouldn't just hardcode the path in the ebuild or termina. But we aren't any worse off than upstream distros using Xwayland. Hardcoding the path in the systemd unit isn't great either, but if we add more distros in the future we can handle this in bazel, since we'll need to generate per-distro packages anyway.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/f83ce6a1bfe149ef1a526a7a02c850a10ee88051

commit f83ce6a1bfe149ef1a526a7a02c850a10ee88051
Author: Stephen Barber <smbarber@chromium.org>
Date: Tue Oct 23 00:38:07 2018

vm_tools: sommelier: allow setting X font path

BUG= chromium:893392 
TEST=xlsfonts shows basic X11 fonts

Change-Id: Iae7361b4ad224b498a0760a362b40b06e414a079
Reviewed-on: https://chromium-review.googlesource.com/1292198
Commit-Ready: Stephen Barber <smbarber@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: David Reveman <reveman@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/f83ce6a1bfe149ef1a526a7a02c850a10ee88051/vm_tools/sommelier/sommelier.c

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/containers/cros-container-guest-tools/+/0972f778607fed97c9eef35a7197b6aad94d23f7

commit 0972f778607fed97c9eef35a7197b6aad94d23f7
Author: Stephen Barber <smbarber@chromium.org>
Date: Tue Oct 23 06:48:38 2018

cros-sommelier: set up X fonts path

BUG= chromium:893392 
TEST=xlsfonts shows basic X11 fonts
CQ-DEPEND=CL:1292198

Change-Id: I51b51604887a75ce9ff428cc5caf1725cf2d3ece
Reviewed-on: https://chromium-review.googlesource.com/1292767
Commit-Ready: Stephen Barber <smbarber@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>

[modify] https://crrev.com/0972f778607fed97c9eef35a7197b6aad94d23f7/cros-sommelier/BUILD
[modify] https://crrev.com/0972f778607fed97c9eef35a7197b6aad94d23f7/cros-sommelier/sommelier-x@.service

Verified on 72.