The systemd stop job timeout defaults to 90s. Does NixOS have a configuration parameter to change this value?
Add the following to your
systemd.extraConfig = '' DefaultTimeoutStopSec=10s '';
I don't know about NixOS specifically, but
man systemd-system.conf for me lists
DefaultTimeoutStopSec= as the default timeout for ... stopping of units. A local administrator would typically change this in
/etc/systemd/system.conf. A Unit can have its own