macOS Containers and defaults

from blog The Desolation of Blog, | ↗ original
This is a follow-up to the article Enabling the Debug menu in Safari 14 on Big Sur and Catalina by Dan Moren. In the past, you could enable the hidden Debug menu in Safari by using the command defaults write com.apple.Safari IncludeInternalDebugMenu -bool true in Terminal app. However, Dan discovered that this no longer worked for him, and he was forced to manually edit a plist file in order to enable the Debug menu. So what happened here? This is the question my blog post will answer.