Pseudo-terminal will not be allocated because stdin is not a terminal.

[roberth]

When stdin is /dev/null (forcing non-interactive use), this message appears.
It suggests that the deployment behavior is dependent on whether nixops runs with a tty or not. This is not great. It'd be good for nixops to always create the tty, but strip colors if needed, just like nix does with its derivation builder processes.

[steve-chavez]

I think this should be tagged "nixops 1->2 regression". I can confirm it not happening on nixops 1.7.