Version Used:
Version 17.7.0 Preview 2.0 [33730.573.main]

Steps to Reproduce:

class C { int P { get; set; } }

class C { [field: Obsolete]int P { get; set; } }

Syntactic update of the property is produced but FindChangedAttributes doesn't find the attribute since it's applied to the field and not the property. The code might need to look for attributes on all symbols synthesized for the given symbol for which attributes might be specified via attribute target. The symbol API however does not provide access to the backing field symbol from IPropertySymbol.

Expected Behavior:

Update.

Actual Behavior:

No update.