Improve VS Code debugger support

.vscode/launch.json

@@ -3,9 +3,18 @@
   "configurations": [
     {
       "type": "rdbg",
-      "name": "Attach with rdbg",
+      "name": "Debug Homebrew command",
+      "request": "launch",
+      "rdbgPath": "${workspaceFolder}/Library/Homebrew/shims/gems/rdbg",
+      "command": "brew debugger --",
+      "script": "${fileBasenameNoExtension}",
+      "askParameters": true
+    },
+    {
+      "type": "rdbg",
+      "name": "Attach to Homebrew debugger",
       "request": "attach",
-      "rdbgPath": "${workspaceFolder}/Library/Homebrew/vendor/portable-ruby/current/lib/ruby/gems/3.3.0/gems/debug-1.9.1/exe/rdbg",
+      "rdbgPath": "${workspaceFolder}/Library/Homebrew/shims/gems/rdbg",
       "env": {
         "TMPDIR": "/private/tmp/",
       }

Library/Homebrew/dev-cmd/debugger.rb

@@ -11,8 +11,6 @@ module Homebrew
           To pass flags to the command, use `--` to separate them from the `brew` flags.
           For example: `brew debugger -- list --formula`.
         EOS
-        switch "-s", "--stop",
-               description: "Stop at the beginning of the script."
         switch "-O", "--open",
                description: "Start remote debugging over a Unix socket."
 
@@ -28,14 +26,17 @@ module Homebrew
         end
 
         brew_rb = (HOMEBREW_LIBRARY_PATH/"brew.rb").resolved_path
-        nonstop = "1" unless args.stop?
         debugger_method = if args.open?
           "open"
         else
           "start"
         end
 
-        with_env RUBY_DEBUG_NONSTOP: nonstop, RUBY_DEBUG_FORK_MODE: "parent" do
+        env = {}
+        env[:RUBY_DEBUG_FORK_MODE] = "parent"
+        env[:RUBY_DEBUG_NONSTOP] = "1" unless ENV["HOMEBREW_RDBG"]
+
+        with_env(**env) do
           system(*HOMEBREW_RUBY_EXEC_ARGS,
                  "-I", $LOAD_PATH.join(File::PATH_SEPARATOR),
                  "-rdebug/#{debugger_method}",

Library/Homebrew/shims/gems/rdbg

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+export HOMEBREW_RDBG="1"
+
+HOMEBREW_PORTABLE_RUBY_BIN="$(cd "$(dirname "$0")"/../../ && pwd)/vendor/portable-ruby/current/bin/"
+exec "${HOMEBREW_PORTABLE_RUBY_BIN}"rdbg "$@"

bin/brew

@@ -258,6 +258,18 @@ then
     FILTERED_ENV+=("${VAR}=${!VAR}")
   done
 fi
+
+if [[ -n "${HOMEBREW_RDBG:-}" ]]
+then
+  for VAR in "${!RUBY_DEBUG_@}"
+  do
+    # Skip if variable value is empty.
+    [[ -z "${!VAR:-}" ]] && continue
+
+    FILTERED_ENV+=("${VAR}=${!VAR}")
+  done
+fi
+
 unset VAR ENV_VAR_NAMES
 
 exec /usr/bin/env -i "${FILTERED_ENV[@]}" /bin/bash -p "${HOMEBREW_LIBRARY}/Homebrew/brew.sh" "$@"