some snaps fail when $HOME is managed by systemd-homed

[stuart12]

I have two accounts on my laptop . One account has $HOME as a normal directory. My main account (login stu) has $HOME managed by systemd-homed. When I use this account some snaps do not work. The cause is probably that /etc/nsswitch.conf does not have systemd in the passwd, group, shadow and gshadow databases. The snaps work when I use my account with a normal $HOME. I can also make them work by adding an entry for stu in /etc/passwd. You are not meant to do this however because the uid can change and account is meant to be fully managed by homed. Could support for systemd-homed be added to snaps? I presume that it would have to be done in core as was done for mdns. I am running Ubuntu 25.04 (see below). firefox works but I have had some problems saving files without the workaround.

drawio prints an error message and does not open a window. I reported the bug to drawio but that was perhaps the wrong place.

laptop% snap info drawio
name:      drawio
summary:   draw.io
publisher: draw.io (jgraph✓)
store-url: https://snapcraft.io/drawio
license:   unset
description: |
  draw.io desktop
commands:
  - drawio
snap-id:      84JReQ8pcNGJyAbT0gSDiW7OpDkrdaXp
tracking:     latest/stable
refresh-date: today at 10:43 CEST
channels:
  latest/stable:    28.1.2 2025-08-30 (253) 131MB -
  latest/candidate: ↑                             
  latest/beta:      ↑                             
  latest/edge:      28.1.2 2025-08-29 (253) 131MB -
installed:          28.1.2            (253) 131MB -
laptop% snap run --shell  drawio
% getent passwd $USER || echo $USER not found; exit
stu not found
exit
laptop% /snap/bin/drawio 
A JavaScript error occurred in the main process
Uncaught Exception:
SystemError [ERR_SYSTEM_ERROR]: A system error occurred: uv_os_get_passwd returned ENOENT (no such file or directory)
    at Object.userInfo (node:os:305:11)
    at file:///snap/drawio/253/resources/app.asar/node_modules/atomically/dist/constants.js:10:29
    at ModuleJob.run (node:internal/modules/esm/module_job:343:25)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:647:26)
    at async node:electron/js2c/browser_init:2:135238
    at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:132:5)

Same thing with element-desktop. It works with my account with $HOME as a normal directory but fails unable to open a window with $HOME mounted by homed.

laptop% snap info element-desktop 
name:      element-desktop
summary:   A feature-rich client for Matrix.org
publisher: Ken VanDine✪
store-url: https://snapcraft.io/element-desktop
contact:   ken@vandine.org
license:   unset
description: |
  Element is both a secure messenger and a productivity team collaboration app that is ideal for
  group chats while remote working. This chat app uses end-to-end encryption to provide powerful
  video conferencing, file sharing and voice calls.
  
  Element’s features include:
     - Advanced online communication tools
     - Fully encrypted messages to allow safer corporate communication, even for remote workers
commands:
  - element-desktop
snap-id:      nZQQXb6Hap0I2ZF3ZsTeFeh80gXHN8DQ
tracking:     latest/stable
refresh-date: 10 days ago, at 00:43 CEST
channels:
  latest/stable:    1.11.109 2025-08-19 (166) 189MB -
  latest/candidate: ↑                               
  latest/beta:      ↑                               
  latest/edge:      1.11.110 2025-08-28 (168) 189MB -
installed:          1.11.109            (166) 189MB -
laptop%  snap run --shell element-desktop
% getent passwd $USER || echo $USER not found; exit
stu not found
exit
laptop% /snap/bin/element-desktop 
A JavaScript error occurred in the main process
Uncaught Exception:
SystemError [ERR_SYSTEM_ERROR]: A system error occurred: uv_os_get_passwd returned ENOENT (no such file or directory)
    at Object.userInfo (node:os:305:11)
    at file:///snap/element-desktop/166/opt/Element/resources/app.asar/node_modules/atomically/dist/constants.js:10:29
    at ModuleJob.run (node:internal/modules/esm/module_job:329:25)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:644:26)
    at async node:electron/js2c/browser_init:2:135156

laptop% uname -srvmpio && cat /etc/issue
Linux 6.14.0-28-generic #28-Ubuntu SMP PREEMPT_DYNAMIC Wed Jul 23 12:05:14 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
Ubuntu 25.04 \n \l

laptop% cat /etc/nsswitch.conf 
# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc-reference' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.

passwd:         files systemd sss
group:          files systemd sss
shadow:         files systemd sss
gshadow:        files systemd

hosts:          files mdns4_minimal [NOTFOUND=return] dns
networks:       files

protocols:      db files
services:       db files sss
ethers:         db files
rpc:            db files

netgroup:       nis sss
automount:  sss