chore: initial commit

lib/utils/mkNakedShell.nix

@@ -0,0 +1,70 @@
+{
+  bashInteractive,
+  coreutils,
+  stdenv,
+  writeTextFile,
+}: let
+  bashPath = "${bashInteractive}/bin/bash";
+  nakedStdenv = writeTextFile {
+    name = "naked-stdenv";
+    destination = "/setup";
+    text = ''
+      # Fix for `nix develop`
+      : ''${outputs:=out}
+
+      runHook() {
+        eval "$shellHook"
+        unset runHook
+      }
+    '';
+  };
+in
+  {
+    name,
+    # A path to a buildEnv that will be loaded by the shell.
+    # We assume that the buildEnv contains an ./env.bash script.
+    profile,
+    meta ? {},
+    passthru ? {},
+  }:
+    (derivation {
+      inherit name;
+
+      system = stdenv.hostPlatform.system;
+
+      # `nix develop` actually checks and uses builder. And it must be bash.
+      builder = bashPath;
+
+      # Bring in the dependencies on `nix-build`
+      args = [
+        "-ec"
+        "${coreutils}/bin/ln -s ${profile} $out; exit 0"
+      ];
+
+      # $stdenv/setup is loaded by nix-shell during startup.
+      # https://github.com/nixos/nix/blob/377345e26f1ac4bbc87bb21debcc52a1d03230aa/src/nix-build/nix-build.cc#L429-L432
+      stdenv = nakedStdenv;
+
+      # The shellHook is loaded directly by `nix develop`. But nix-shell
+      # requires that other trampoline.
+      shellHook = ''
+        # Remove all the unnecessary noise that is set by the build env
+        unset NIX_BUILD_TOP NIX_BUILD_CORES NIX_STORE
+        unset TEMP TEMPDIR TMP TMPDIR
+        unset builder out shellHook stdenv system name
+        # Flakes stuff
+        unset dontAddDisableDepTrack outputs
+
+        # For `nix develop`. We get /noshell on Linux and /sbin/nologin on macOS.
+        if [[ "$SHELL" == "/noshell" || "$SHELL" == "/sbin/nologin" ]]; then
+          export SHELL=${bashPath}
+        fi
+
+        # Load the environment
+        source "${profile}/env.bash"
+      '';
+    })
+    // {
+      inherit meta passthru;
+    }
+    // passthru