37e42d01a0
nixos-enter sets up /etc/resolv.conf as a bind mount from the host system, so trying to activate a system that sets `environment.etc."resolv.conf"` (e.g. with systemd-resolved enabled) results in an unhelpful warning. Skip linking /etc/resolv.conf if we're in a nixos-enter environment, as determined by the IN_NIXOS_ENTER environment variable. Make the warnings more helpful, indicating which file we failed to link. Unlink temporary files in case of failure.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at https://nixos.org/nixos and in the manual in doc/manual.