watchman: add update script to bulk update all the Facebook stuff

pkgs/by-name/wa/watchman/package.nix

@@ -103,7 +103,7 @@ stdenv.mkDerivation (finalAttrs: {
     remove-references-to -t ${folly.fmt.dev} $out/bin/*
   '';
 
-  passthru.updateScript = nix-update-script { };
+  passthru.updateScript = ./update.sh;
 
   meta = {
     description = "Watches files and takes action when they change";

pkgs/by-name/wa/watchman/update.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p nix-update cargo
+# shellcheck shell=bash
+
+set -euf -o pipefail
+
+# toposorted manually, please keep in order
+PACKAGES=(
+    "folly"
+    "fizz"
+    "mvfst"
+    "wangle"
+    "fbthrift"
+    "fb303"
+    "edencommon"
+)
+
+for P in "${PACKAGES[@]}"; do
+    nix-update "$P" --commit
+done
+
+nix-update watchman --commit --generate-lockfile --lockfile-metadata-path "watchman/cli"