Can't set HelpViewer defaults

[jamtur01]

When running Nix-darwin (MBP Apple Max M4) I see

building the system configuration...
user defaults...
2025-03-19 12:05:22.276 defaults[18813:50714676] Could not write domain /Users/jamtur01/Library/Containers/com.apple.helpviewer/Data/Library/Preferences/com.apple.helpviewer; exiting

I have this in my config:

"com.apple.helpviewer" = { DevMode = true; };

If I comment it out, then it works.

This is happening since 15.3.1 (24D70).