[Desktop] - Steam Deck fails to switch to Desktop mode when the "Home" partition is full.

[ZereoX]

Your system information

• Steam client version (build number or date): 1731990050 (Stable) / 1732590255 (Beta)
• SteamOS version: 3.6.20 / 3.7.0
• Opted into Steam client beta?: Yes. Issue is present on both Stable and Beta
• Opted into SteamOS beta?: Yes. Issue is present on both Stable and Beta
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

On Steam Deck, attempting to Switch to Desktop while the Home partition (i.e. /home/deck/) is full will cause KDE / Plasma to fail. The user might be shown a Plasma Workspace installation problem! prompt follow by repeat KDE Crash Handler (I've seen instances when reproducing the issue where nothing was displayed). The user will eventually remain stuck on a black screen and will need to power cycle the device to recover it.

Video

Desktop_Mode_Failure.mp4

Steps for reproducing this issue:

1. Open the SteamOS Devkit Client.
2. Select the target device and chose Remote Shell
3. Run the following command: fallocate -l 500G temp
4. Navigate to Steam > Power
5. Select Switch to Desktop.

Reproduction Rate: 5/5

Affected Platforms

• LCD / Jupiter: Yes
• OLED / Galileo: Yes
• Desktop Deck-like session (gamescope -e -- steam -gamepadui -steamdeck): N/A
• Desktop: N/A

Note: The issue is marked as N/A for Desktop as this ticket is specifically to track and improve the behaviour on SteamOS / Steam Deck (i.e. on device recovery), but a general issue relating to low disk space for Steam was flagged here: ValveSoftware/steam-for-linux#11517

Actual result

• Steam Deck fails to transition to Desktop mode and remain stuck on a black screen.

Expected result

• Plasma session can reliably start even if the home partition is full.

Notes

• System Report: 64GB_System_Report.log

[bertogg]

Same as #893, we should probably close the older issue and it is a bit old already.