--- a/Parser.st	Fri Nov 29 20:44:26 2019 +0100
+++ b/Parser.st	Sun Dec 01 05:31:53 2019 +0100
@@ -4996,12 +4996,21 @@
 !
 
 warnIfPossiblyUninitializedLocal:expr
+    |msg|
+
     parserFlags warnAboutPossiblyUninitializedLocals ifFalse:[
         ^ self.
     ].
     (self isPossiblyUninitializedLocal:expr) ifTrue:[
+        msg := '"%1" is uninitialized here (always nil).'.
+        (expr parent notNil 
+          and:[expr parent isMessage
+          and:[expr parent selector = '='
+        ]]) ifTrue:[
+            msg := msg,c'\n"=" is comparing - did you mean ":=" for assignment?'
+        ].
         self
-            warning:'"',expr name,'" is uninitialized here (always nil)'
+            warning:(msg  bindWith:expr name)
             doNotShowAgainAction:[ 
                 parserFlags warnAboutPossiblyUninitializedLocals:false. 
                 ParserFlags warnAboutPossiblyUninitializedLocals:false.