diff --git a/.devcontainer/on-create-command.sh b/.devcontainer/on-create-command.sh
index 63285db4c5..c5a5666bdb 100755
--- a/.devcontainer/on-create-command.sh
+++ b/.devcontainer/on-create-command.sh
@@ -21,6 +21,9 @@ brew install shellcheck shfmt gh gnu-tar
 # cleanup any mess
 brew cleanup
 
+# actually tap homebrew/core, no longer done by default
+brew tap homebrew/core
+
 # install some useful development things
 sudo apt-get update
 
diff --git a/Library/Homebrew/rubocops/files.rb b/Library/Homebrew/rubocops/files.rb
index 7ee1de87d5..63d3d7566a 100644
--- a/Library/Homebrew/rubocops/files.rb
+++ b/Library/Homebrew/rubocops/files.rb
@@ -13,6 +13,9 @@ module RuboCop
         def audit_formula(node, _class_node, _parent_class_node, _body_node)
           return unless file_path
 
+          # Codespaces routinely screws up all permissions so don't complain there.
+          return if ENV["CODESPACES"] || ENV["HOMEBREW_CODESPACES"]
+
           offending_node(node)
           actual_mode = File.stat(file_path).mode
           # Check that the file is world-readable.