Linux_host desktop fails with "no implicit conversion of nil into String"

Hi folks, just getting started on Alma 8 with rpm-based OnDemand v. 2.0.23. I have a trivial linux_host cluster set up; file browser and ssh/shell access are working fine. When I try to start a desktop session, I’m getting the above error. Without more information (file? line number? stack trace?), I’m not sure where to go next. I’m not doing any containerizing, for the moment just trying to get a browser-based Linux desktop working on the host OS. Nothing useful in any of the logs I’ve seen. Any helpful debugging next steps are most appreciated. Thanks!

Relevant files follow…

cat /etc/ood/config/clusters.d/davidtest.yml


v2:
metadata:
title: “davidtest”
login:
host: “davidtest.domain.edu”
job:
adapter: “linux_host”
submit_host: “davidtest.domain.edu”
ssh_hosts: # These are the actual login nodes
- davidtest.domain.edu
site_timeout: 7200
debug: true
tmux_bin: /usr/bin/tmux

cat /etc/ood/config/apps/bc_desktop/davidtest.yml


title: “Davidtest Desktop”
description: “XFCE desktop on davidtest”
cluster: “davidtest”
attributes:
desktop: “xfce”

Hi and welcome!

You may have a log entry in /var/log/ondemand-nginx/$USER/error.log.

But you’re right, without it it’s hard to saw where it’s coming from without that. I can’t exactly tell if your YAML correctly formatted, but I’d guess it is and it looks to be complete. Let’s hope there’s a message for us in that log.

Hey Jeff, yeah, checked that, unfortunately, nothing more what displays on the browser:

App 21942 output: [2022-06-10 14:49:28 -0500 ] INFO “execve = [“git”, “describe”, “–always”, “–tags”]”
App 21942 output: [2022-06-10 14:49:28 -0500 ] INFO “method=GET path=/pun/sys/dashboard/batch_connect/sys/bc_desktop/davidtest/session_contexts/new format=html controller=BatchConnect::SessionContextsController action=new status=200 duration=24.09 view=14.63”
App 21942 output: [2022-06-10 14:49:38 -0500 ] ERROR “ERROR: TypeError - no implicit conversion of nil into String”
App 21942 output: [2022-06-10 14:49:38 -0500 ] INFO “execve = [“git”, “describe”, “–always”, “–tags”]”
App 21942 output: [2022-06-10 14:49:38 -0500 ] INFO “method=POST path=/pun/sys/dashboard/batch_connect/sys/bc_desktop/davidtest/session_contexts format=html controller=BatchConnect::SessionContextsController action=create status=200 duration=91.94 view=15.03”

Can you share the app’s form YAML? I’m guessing some misconfiguration/something about that file is throwing this off.