How do I upgrade from NixOS 24.11 to NixOS 25.05? Is the approach described in Upgrading NixOS in the NixOS Manual the right one? In the past, I read that before a full system upgrade the Nix package manager should be upgraded first, because the system upgrade itself may already need a newer version of the package manager. Isn’t this the case anymore?
nixos-rebuild already takes care of updating nix first, unless you explicitly opt out via --no-build-nix.
You should also probably use nixos-rebuild boot (then reboot) instead of nixos-rebuild switch as the former will actually get you into the new system with new kernel, init, etc.
Okay. Great!
Indeed. I already thought about this.
It’s also worth remembering to read through the release notes as part of the process, particularly the backward incompatibilities before updating; from time to time there are changes that won’t give you explicit warnings/errors.
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