In reply to @toddt:matrix.org
good evening, been trying to setup NixOS-WSL for about 3 hours. When I run initial setup of "sudo nixos-rebuild switch" I get the following error "building '/nix/store/vz70pnvz94w0is3vrpkf6yg7kx2q8d9v-nixos-wsl-utils-1.0.0.drv'...
Running phase: unpackPhase
unpacking source archive /nix/store/mgs739bd2i6v7cjxilwk0qf9czfd8vg9-utils
source root is utils
Executing cargoSetupPostUnpackHook
Finished cargoSetupPostUnpackHook
Running phase: patchPhase
Executing cargoSetupPostPatchHook
Validating consistency between /build/utils/Cargo.lock and /build/cargo-vendor-dir/Cargo.lock
Finished cargoSetupPostPatchHook
Running phase: updateAutotoolsGnuConfigScriptsPhase
Running phase: configurePhase
Running phase: buildPhase
Executing cargoBuildHook
++ env CC_X86_64_UNKNOWN_LINUX_GNU=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/cc CXX_X86_64_UNKNOWN_LINUX_GNU=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/c++ CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/cc CC_X86_64_UNKNOWN_LINUX_GNU=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/cc CXX_X86_64_UNKNOWN_LINUX_GNU=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/c++ CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/cc CARGO_BUILD_TARGET=x86_64-unknown-linux-gnu HOST_CC=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/cc HOST_CXX=/nix/store/shdkxxdlpv66wl33rh9d01zfypaka1dn-gcc-wrapper-12.3.0/bin/c++ cargo build -j 16 --target x86_64-unknown-linux-gnu --frozen --profile release
error: package clap_builder v4.5.2 cannot be built because it requires rustc 1.74 or newer, while the currently active rustc version is 1.73.0
Either upgrade to rustc 1.74 or newer, or use
cargo update -p clap_builder@4.5.2 --precise ver
where ver is the latest version of clap_builder supporting rustc 1.73.0
error: builder for '/nix/store/vz70pnvz94w0is3vrpkf6yg7kx2q8d9v-nixos-wsl-utils-1.0.0.drv' failed with exit code 101
error: 1 dependencies of derivation '/nix/store/igsm8s0h1sh02zzx4b60mx8phk7b0bl4-nixos-system-nixos-23.11.7609.5c2ec3a5c2ee.drv' failed to build"

As the error seems to be the same as this thread, I do believe you're on 23.11 and you should simply update to 24.05 to resolve the issue.

Look at https://github.com/nix-community/NixOS-WSL/issues/483 for instructions in one of the comments

warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error:
… <borked>

     at «none»:0: (source not available)

   … while calling the 'import' builtin

     at «string»:1:6:

        1| with import <nixpkgs/nixos> {}; config.system.build.nixos-rebuild
         |      ^

   (stack trace truncated; use '--show-trace' to show the full trace)

   error: file 'nixpkgs/nixos' was not found in the Nix search path (add it using $NIX_PATH or -I)

   at «none»:0: (source not available)

building Nix...
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error: file 'nixpkgs/nixos' was not found in the Nix search path (add it using $NIX_PATH or -I)

   at «none»:0: (source not available)

warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I)

   at «none»:0: (source not available)

warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
error: file 'nixpkgs/nixos/modules/installer/tools/nix-fallback-paths.nix' was not found in the Nix search path (add it using $NIX_PATH or -I)