Drop support for dir-locals.nix, <nixpkgs>, etc.

In the spirit of Marie Kondo, I'm tidying up!

TL;DR:
- Prefer .envrc `use_nix` and delete all dir-locals.nix files
- Remove ~all references to <nixpkgs>, <unstable>, <depot> and prefer
  referencing each with briefcase.third_party.{pkgs,unstable,depot}
- Delete nixBufferFromShell function since I was only using that in
  dir-locals.nix files

3 files changed, 9 insertions, 12 deletions

diff --git a/tools/url-blocker/.envrc b/tools/url-blocker/.envrc
index 1abb058f60d5..a4a62da526d3 100644
--- a/tools/url-blocker/.envrc
+++ b/tools/url-blocker/.envrc
@@ -1 +1,2 @@
 source_up
+use_nix
diff --git a/tools/url-blocker/default.nix b/tools/url-blocker/default.nix
index 5d1b8cd1666a..943644e5f542 100644
--- a/tools/url-blocker/default.nix
+++ b/tools/url-blocker/default.nix
@@ -1,8 +1,6 @@
-{ ... }:
+{ pkgs, ... }:
 
 let
-  pkgs = import <unstable> {};
-
   ghc = pkgs.haskellPackages.ghcWithPackages (hpkgs: [
     hpkgs.time
     hpkgs.aeson
diff --git a/tools/url-blocker/shell.nix b/tools/url-blocker/shell.nix
index 40f217e3f9a7..1adc566c0121 100644
--- a/tools/url-blocker/shell.nix
+++ b/tools/url-blocker/shell.nix
@@ -1,12 +1,10 @@
 let
-  pkgs = import <unstable> {};
-in pkgs.mkShell {
-  buildInputs = with pkgs; [
-    (haskellPackages.ghcWithPackages (hpkgs: with hpkgs; [
-      time
-      aeson
-      either
-      hspec
-    ]))
+  briefcase = import <briefcase> {};
+in briefcase.buildHaskell.shell {
+  deps = hpkgs: with hpkgs; [
+    time
+    aeson
+    either
+    hspec
   ];
 }