To use Nix, some environment variables should be set. In particular, PATH should contain the directories prefix/bin and ~/.nix-profile/bin. The first directory contains the Nix tools themselves, while ~/.nix-profile is a symbolic link to the current user environment
I’m assuming “prefix” means /nix. I installed Nix and it works but my $PATH doesn’t include /nix/bin. And /nix/bin doesn’t even exist. Is this an error in the manual or am I not understanding it?
prefix is Autotools terminology¹. It refers to the path Nix was installed to. It will be something like /nix/store/frsdhkhqd7fpzbmnzd9zmvq9klw20svm-nix-2.2.2. Though, we usually do not add prefix/bin to $PATH directly – instead, when we install Nix, it is symlinked to a profile (for example, under /run/current-system/sw/bin or ~/.nix-profile/bin) and that is added to $PATH.