Cloning builder process: Operation not permitted when using Nix (under Linux) update channel

I use Arch Linux 4.19.15-1-lts #1 SMP Sun Jan 13 13:53:52 CET 2019 x86_64 GNU/Linux. I do also have Nix installed: nix-env (Nix) 2.2. I've never had any problems until the recent update to version 2.2. I always do the upgrades/updates with these two steps: $ nix-channel --update ... $ nix-env --upgrade ... ...but after the recent 2.2 update I can't find a way to make nix-channel --update work anymore. I'm always getting these errors: error: cloning builder process: Operation not permitted error: unable to start build process error: program '/nix/store/876x7a35qbn3q062b6zcz6va88m0990d-nix-2.2/bin/nix-env' failed with exit code 1 ...even if I do rollback the previous operation(s): $ nix-channel --update unpacking channels... error: cloning builder process: Operation not permitted error: unable to start build process error: program '/nix/store/876x7a35qbn3q062b6zcz6va88m0990d-nix-2.2/bin/nix-env' failed with exit code 1 $ nix-channel --rollback switching from generation 40 to 39 $ nix-channel --update unpacking channels... error: cloning builder process: Operation not permitted error: unable to start build process error: program '/nix/store/876x7a35qbn3q062b6zcz6va88m0990d-nix-2.2/bin/nix-env' failed with exit code 1 This is what I have in the update list: $ nix-channel --list nixpkgs https://nixos.org/channels/nixpkgs-unstable ...and eventually I can't even delete that: $ nix-channel --remove nixpkgs uninstalling 'nixpkgs-19.03pre165281.7d864c6bd63' error: cloning builder process: Operation not permitted error: unable to start build process error: program '/nix/store/876x7a35qbn3q062b6zcz6va88m0990d-nix-2.2/bin/nix-env' failed with exit code 1 > I would like to avoid a reinstall. --- **UPDATE** I couldn't wait! O:) I went ahead and removed the current installation...and when I do a fresh install I basically got the same result: $ sh <(curl https://nixos.org/nix/install) --no-daemon % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 2476 100 2476 0 0 5417 0 --:--:-- --:--:-- --:--:-- 5406 downloading Nix 2.2.1 binary tarball for x86_64-linux from 'https://nixos.org/releases/nix/nix-2.2.1/nix-2.2.1-x86_64-linux.tar.bz2 ' to '/tmp/nix-binary-tarball-unpack.n5vqvsi4Uq'... % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 22.5M 100 22.5M 0 0 4016k 0 0:00:05 0:00:05 --:--:-- 4377k Note: a multi-user installation is possible. See https://nixos.org/nix/manual/#sect-multi-user-installation performing a single-user installation of Nix... directory /nix does not exist; creating it by running 'mkdir -m 0755 /nix && chown x80486 /nix' using sudo [sudo] password for x80486: copying Nix to /nix/store................................. initialising Nix database... Nix: creating /home/x80486/.nix-profile installing 'nix-2.2.1' error: cloning builder process: Operation not permitted error: unable to start build process /tmp/nix-binary-tarball-unpack.n5vqvsi4Uq/unpack/nix-2.2.1-x86_64-linux/install: unable to install Nix into your default profile ...so looks like there is, in general, something going on with Linux (or specifically the distro that use) and Nix.