override toolchain '$HOME/redox/redox-nix/redox/prefix/x86_64-unknown-redox/relibc-install' is not installed

My exact steps:

$ git clone --recurse-submodules https://gitlab.redox-os.org/redox-os/redox-nix
$ cd redox-nix
$ nix run -f ./components redoxer
$ redoxer install

I got the following error while running that last command:

error: override toolchain '/home/ajanse/redox/redox-nix/redox/prefix/x86_64-unknown-redox/relibc-install' is not installed
error: caused by: the RUSTUP_TOOLCHAIN environment variable specifies an uninstalled toolchain
redoxer cargo: exit code: 1

Any idea what could be causing this?