bin/nixos-shell: use nix run

Use `nix run` instead of puttling the `result` in a temporary directory
and run the executable with a glob pattern.

Author: ShamrockLee

bin/nixos-shell

@@ -53,27 +53,21 @@ done
 
 unset NIXOS_CONFIG
 
-tempdir=$(mktemp -d)
-cleanup() {
-  rm -rf "$tempdir"
-}
-trap cleanup EXIT SIGINT SIGQUIT ERR
-
 if [[ -z "$flake_uri" ]]; then
   extraBuildFlags+=(
     -I "nixos-config=$nixos_config"
   )
 else
   extraBuildFlags+=(
-    --extra-experimental-features "flakes"
+    --extra-experimental-features "nix-command flakes"
     --argstr flakeStr "$flake"
     --argstr flakeUri "$flake_uri"
     --argstr flakeAttr "${flake_attr:-"vm"}"
   )
 fi
 
-nix-build "${script_dir}/../share/nixos-shell.nix" -A "config.system.build.vm" -k \
-  -o "${tempdir}/result" \
-  "${extraBuildFlags[@]}"
+nix run config.system.build.vm \
+  --file "${script_dir}/../share/nixos-shell.nix" \
+  --keep-going \
+  "${extraBuildFlags[@]}" \
   "$@"
-"${tempdir}/result/bin/"run-*-vm