fixes #3548

compiler/semcall.nim

@@ -145,6 +145,20 @@ proc notFoundError*(c: PContext, n: PNode, errors: CandidateErrors) =
   else:
     localError(n.info, errGenerated, result)
 
+proc bracketNotFoundError(c: PContext; n: PNode) =
+  var errors: CandidateErrors = @[]
+  var o: TOverloadIter
+  let headSymbol = n[0]
+  var symx = initOverloadIter(o, c, headSymbol)
+  while symx != nil:
+    if symx.kind in routineKinds:
+      errors.add((symx, 0))
+    symx = nextOverloadIter(o, c, headSymbol)
+  if errors.len == 0:
+    localError(n.info, "could not resolve: " & $n)
+  else:
+    notFoundError(c, n, errors)
+
 proc resolveOverloads(c: PContext, n, orig: PNode,
                       filter: TSymKinds;
                       errors: var CandidateErrors): TCandidate =

compiler/semexprs.nim

@@ -1390,15 +1390,16 @@ proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
     # --> `[]=`(a, i, x)
     let oldBracketExpr = c.p.bracketExpr
     a = semSubscript(c, a, {efLValue})
-    if a == nil and mode != noOverloadedSubscript:
+    if a == nil:
       result = buildOverloadedSubscripts(n.sons[0], getIdent"[]=")
       add(result, n[1])
-      result = semExprNoType(c, result)
-      c.p.bracketExpr = oldBracketExpr
-      return result
-    elif a == nil:
-      localError(n.info, "could not resolve: " & $n[0])
-      return n
+      if mode == noOverloadedSubscript:
+        bracketNotFoundError(c, result)
+        return n
+      else:
+        result = semExprNoType(c, result)
+        c.p.bracketExpr = oldBracketExpr
+        return result
     c.p.bracketExpr = oldBracketExpr
   of nkCurlyExpr:
     # a{i} = x -->  `{}=`(a, i, x)

compiler/semmagic.nim

@@ -42,7 +42,10 @@ proc semArrGet(c: PContext; n: PNode; flags: TExprFlags): PNode =
   result = semSubscript(c, result, flags)
   c.p.bracketExpr = oldBracketExpr
   if result.isNil:
-    localError(n.info, "could not resolve: " & $n)
+    let x = copyTree(n)
+    x.sons[0] = newIdentNode(getIdent"[]", n.info)
+    bracketNotFoundError(c, x)
+    #localError(n.info, "could not resolve: " & $n)
     result = n
 
 proc semArrPut(c: PContext; n: PNode; flags: TExprFlags): PNode =