updating README

README.md

@@ -1,10 +1,11 @@
 # Mini Compile Commands
 
-Mini compile commands instruments the compiler wrappers in nixpkgs to generate `compile_commands.json` files. Using a version of nixpkgs which has mini compile commands, it can be included in a `shell.nix` as follows:
+Mini compile commands instruments the compiler wrappers in nixpkgs to generate `compile_commands.json` files. Using a version of nixpkgs after [this PR](https://github.com/NixOS/nixpkgs/pull/197937), it can be included in a `shell.nix` as follows:
 
 ```
 with (import <nixpkgs> {});
-(mkShell.override {stdenv = ( mini-compile-commands.wrap clang13Stdenv );}) {
+let mini-compile-commands = callPackage <this_repo> {};
+in (mkShell.override {stdenv = ( mini-compile-commands.wrap stdenv );}) {
    buildInputs = [ cmake gtest ];
 }
 ```
@@ -13,18 +14,12 @@ When the compiler is invoked, it will send a message to `mini_compile_commands_s
 
 https://user-images.githubusercontent.com/8081722/192353380-5c417134-1cf5-4f60-97c1-386f24b0d4f7.mp4
 
-## Examples
+## Example
 
 Mini compile commands can be used to generate a `compile_commands.json` for the linux kernel:
 
 ```
-nix-shell -E "with (import <nixpkgs> {}); linux.override { stdenv = (mini-compile-commands.wrap stdenv); }"
-```
-
-or nix itself:
-
-```
-nix-shell -E "with (import <nixpkgs> {}); nix.override { stdenv = (mini-compile-commands.wrap stdenv); }"
+nix-shell -E "with (import <nixpkgs> {}); let mini-compile-commands = callPackage <this_repo> {}; in linux.override { stdenv = (mini-compile-commands.wrap stdenv); }"
 ```
 
 As demonstrated in the above video, create two shells. In one, run `mini_compile_commands_server.py compile_commands.json` and in the other, run your build command.