NixOS 21.05 installation failed (installing from an existing distro)

I tried the nix-build workaround before nixos-install and it worked!
https://github.com/NixOS/nixpkgs/issues/126141#issuecomment-861720372

The installation seems perfect, everything booted without any problem.
But in the nixos-install step I’ve been getting perl locale warning (even after setting LOCALE_ARCHIVE)
and systemd-tempfiles chroot error.
Are these errors/warnings concerning?

nixos-install output:

...
building '/nix/store/rhj6kdyz6hfzdj7xzl0rx3ymj7r3rl18-unit-reload-systemd-vconsole-setup.service.drv'...
building '/nix/store/m6sqqz5v2zfspd17n53gsjqk0zfh041j-wait-for-pstore.sh.drv'...
building '/nix/store/4xf9ylib1khslsdr23xdyw03hqz656qa-xlock.pam.drv'...
building '/nix/store/gqli9srxkhwg4w0i4i26dshm8971kf8b-unit-mount-pstore.service.drv'...
building '/nix/store/pzgvb2vkv4fffyq6yfb3i2hjwy94m9f9-xscreensaver.pam.drv'...
building '/nix/store/by5jxnqcnlz4ampb2bl562jjplj777nc-system-units.drv'...
building '/nix/store/03w8imrnpzk047g1563w11pry2j8mkni-etc.drv'...
building '/nix/store/24d2p60zq3gis6ygfj6394352w3bi5ib-nixos-system-nixos-21.05.1139.20d353f6491.drv'...
/nix/store/91nyn21naw5b750393km5zpav1vhj5yn-nixos-system-nixos-21.05.1139.20d353f6491
installing the boot loader...
setting up /etc...
chroot: failed to run command ‘systemd-tmpfiles’: No such file or directory
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
        LANGUAGE = "",
        LC_ALL = (unset),
        LANG = "en_IN.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
updating GRUB 2 menu...
setting up /etc...
chroot: failed to run command ‘systemd-tmpfiles’: No such file or directory
setting up /etc...
chroot: failed to run command ‘systemd-tmpfiles’: No such file or directory
setting root password...
New password: 
Retype new password: 
passwd: password updated successfully
installation finished!