Try a NixOS virtual machine¶

On an x86_64-linux machine with KVM, the starter can boot a small NixOS system with the same user environment. It uses a serial console, so you do not need a graphical session or the full desktop packages.

In the copied starter directory:

nix build .#vm --out-link result-vm
./result-vm/bin/run-nix-guide-vm

The console signs in to the disposable learner account. This convenient login belongs only to the VM example. Do not copy it into a real machine installation.

Try git config --get init.defaultBranch, git init /tmp/example, and git st inside that repository. You should see the configured branch and alias behavior. Use Ctrl+A followed by X to stop the serial VM. Its disk lives in the directory where you launch it; retain it to continue experimenting or remove the example's .qcow2 disk after shutdown to start fresh. Do not delete unrelated VM images.

Run the automated exercise¶

nix build .#checks.x86_64-linux.vm-runtime -L

The test boots the example, waits for Home Manager activation, and exercises the configured Git and shell behavior. It uses disposable test disks. Evaluation, generated-file checks, and this runtime test each cover a different part of the configuration.

The test requires KVM access. A permission failure involving /dev/kvm is a host setup problem, not proof of a broken Nix module. See the NixOS VM tutorial. A VM does not establish physical GPU, HDR, Bluetooth, or suspend compatibility.