fix(gen-verilog): declare the tuple-destructure temp in test blocks

NOW.md

@@ -2,6 +2,13 @@
 
 Last updated: 2026-08-08
 
+## gen-verilog: tuple-destructure temp declared in test blocks (Refs #1948)
+
+- A test-block `let (a, b) = call()` slices a packed temp `__tup_l{line}`, but that temp (and the element regs) are declared only in emit_local's Decl phase, which the TB Init-only path skips -- the temp was referenced undeclared ("Could not find variable __tup_l242")
+- The top-of-block declaration pass now emits the tuple-destructure decls (emit_local Decl) for empty-name/extra_field locals
+- tri-net corpus: icarus 96 -> 97 (cross_layer_optimizer)
+- FROZEN_HASH resealed
+
 ## gen-verilog: `_` discard in tuple destructure gets a throwaway reg (Refs #1948)
 
 - `(link1, _) = create_2node_mesh(50)` emitted `{_, link1} = call()` -- Verilog has no `_` wildcard, so iverilog could not find the variable

bootstrap/src/compiler.rs

@@ -8479,6 +8479,17 @@ impl VerilogCodegen {
                     self.write_indent();
                     self.emit_local(child, LocalEmitPhase::Decl);
                 }
+                // Tuple-destructure local `let (a, b) = call()`: the packed temp
+                // (__tup_l{line}) and the element regs are declared only in the
+                // Decl phase, which the TB Init-only path skips -- so the temp
+                // was referenced undeclared ("Could not find variable
+                // __tup_l242"). Declare them at the top of the block here.
+                if child.kind == NodeKind::StmtLocal
+                    && child.name.is_empty()
+                    && !child.extra_field.is_empty()
+                {
+                    self.emit_local(child, LocalEmitPhase::Decl);
+                }
                 // Pre-declare a probe for every assert_eq in the block.
                 let stmt = if child.kind == NodeKind::StmtExpr {
                     child.children.first()

bootstrap/stage0/FROZEN_HASH

@@ -1 +1 @@
-fbbe3e1568e833b001e94be2d4cb612011d41d1e38fb5b57bca42e91ca510fb4
+df2991ce372f7f3ecb9de196116662a7a40f2490cdeeb75ca77b2df18dfbb5fd

docs/NOW.md

@@ -2,6 +2,13 @@
 
 Last updated: 2026-08-08
 
+## gen-verilog: tuple-destructure temp declared in test blocks (Refs #1948)
+
+- A test-block `let (a, b) = call()` slices a packed temp `__tup_l{line}`, but that temp (and the element regs) are declared only in emit_local's Decl phase, which the TB Init-only path skips -- the temp was referenced undeclared ("Could not find variable __tup_l242")
+- The top-of-block declaration pass now emits the tuple-destructure decls (emit_local Decl) for empty-name/extra_field locals
+- tri-net corpus: icarus 96 -> 97 (cross_layer_optimizer)
+- FROZEN_HASH resealed
+
 ## gen-verilog: `_` discard in tuple destructure gets a throwaway reg (Refs #1948)
 
 - `(link1, _) = create_2node_mesh(50)` emitted `{_, link1} = call()` -- Verilog has no `_` wildcard, so iverilog could not find the variable