macos – Binary plist is opened as plain text in Xcode

# file /private/var/root/Library/Preferences/com.apple.finder.plist
/private/var/root/Library/Preferences/com.apple.finder.plist: Apple binary property list

Opened in Xcode 10.1:
Xcode bug
If I use plutil -convert xml1 file.plist, Xcode can open it correctly. What might cause this behavior? How can I tell Xcode to treat it as a binary plist file?