[Nix-dev] "Failed to execute login command"

[Bjørn Forsman]

Hi,

Since about a month now, whenever I do "nixos-rebuild switch" (after
also updating channel sources) I'm being kicked out of the desktop
environment and cannot login graphically unless I reboot (maybe there
is a way to recover, but haven't yet bothered to investigate that
further).

When this happens, I get the message "Failed to execute login command"
(or something similar) in the middle of the screen in a "graphical"
big font. After a second or two I see a text console (ctrl-alt-f1?)
and then back to the "Failed to execute login command".

Anyone else getting these?

The problem "fixes itself" by rebooting. But it's very annoying. I'm
running nixos unstable with gnome3.12 and lightdm login manager.

Best regards,
Bjørn Forsman