diff --git a/src/AstGen.zig b/src/AstGen.zig
index 3850fe84a78fd841ca8b41718d957ea1118d6138..e30913ac76e4459136e5c075a278c230bf0f7a96 100644
--- a/src/AstGen.zig
+++ b/src/AstGen.zig
@@ -2696,6 +2696,7 @@ fn genDefers(
                             break :blk &local_val_scope.base;
                         };
                         try unusedResultDeferExpr(gz, defer_scope, sub_scope, expr_node);
+                        try checkUsed(gz, scope, sub_scope);
                         try gz.addDbgBlockEnd();
                     },
                     .normal_only => continue,
@@ -5384,7 +5385,7 @@ fn ifExpr(
             const tag: Zir.Inst.Tag = if (payload_is_ref) .is_non_err_ptr else .is_non_err;
             break :c .{
                 .inst = err_union,
-                .bool_bit = try block_scope.addUnNode(tag, err_union, node),
+                .bool_bit = try block_scope.addUnNode(tag, err_union, if_full.ast.cond_expr),
             };
         } else if (if_full.payload_token) |_| {
             const cond_rl: ResultLoc = if (payload_is_ref) .ref else .none;
@@ -5392,7 +5393,7 @@ fn ifExpr(
             const tag: Zir.Inst.Tag = if (payload_is_ref) .is_non_null_ptr else .is_non_null;
             break :c .{
                 .inst = optional,
-                .bool_bit = try block_scope.addUnNode(tag, optional, node),
+                .bool_bit = try block_scope.addUnNode(tag, optional, if_full.ast.cond_expr),
             };
         } else {
             const cond = try expr(&block_scope, &block_scope.base, bool_rl, if_full.ast.cond_expr);
@@ -5423,7 +5424,7 @@ fn ifExpr(
                     .err_union_payload_unsafe_ptr
                 else
                     .err_union_payload_unsafe;
-                const payload_inst = try then_scope.addUnNode(tag, cond.inst, node);
+                const payload_inst = try then_scope.addUnNode(tag, cond.inst, if_full.ast.then_expr);
                 const token_name_index = payload_token + @boolToInt(payload_is_ref);
                 const ident_name = try astgen.identAsString(token_name_index);
                 const token_name_str = tree.tokenSlice(token_name_index);
@@ -5452,7 +5453,7 @@ fn ifExpr(
             const ident_bytes = tree.tokenSlice(ident_token);
             if (mem.eql(u8, "_", ident_bytes))
                 break :s &then_scope.base;
-            const payload_inst = try then_scope.addUnNode(tag, cond.inst, node);
+            const payload_inst = try then_scope.addUnNode(tag, cond.inst, if_full.ast.then_expr);
             const ident_name = try astgen.identAsString(ident_token);
             try astgen.detectLocalShadowing(&then_scope.base, ident_name, ident_token, ident_bytes);
             payload_val_scope = .{
@@ -5495,7 +5496,7 @@ fn ifExpr(
                     .err_union_code_ptr
                 else
                     .err_union_code;
-                const payload_inst = try else_scope.addUnNode(tag, cond.inst, node);
+                const payload_inst = try else_scope.addUnNode(tag, cond.inst, if_full.ast.cond_expr);
                 const ident_name = try astgen.identAsString(error_token);
                 const error_token_str = tree.tokenSlice(error_token);
                 if (mem.eql(u8, "_", error_token_str))
@@ -5709,7 +5710,7 @@ fn whileExpr(
             const tag: Zir.Inst.Tag = if (payload_is_ref) .is_non_err_ptr else .is_non_err;
             break :c .{
                 .inst = err_union,
-                .bool_bit = try continue_scope.addUnNode(tag, err_union, node),
+                .bool_bit = try continue_scope.addUnNode(tag, err_union, while_full.ast.then_expr),
             };
         } else if (while_full.payload_token) |_| {
             const cond_rl: ResultLoc = if (payload_is_ref) .ref else .none;
@@ -5717,7 +5718,7 @@ fn whileExpr(
             const tag: Zir.Inst.Tag = if (payload_is_ref) .is_non_null_ptr else .is_non_null;
             break :c .{
                 .inst = optional,
-                .bool_bit = try continue_scope.addUnNode(tag, optional, node),
+                .bool_bit = try continue_scope.addUnNode(tag, optional, while_full.ast.then_expr),
             };
         } else {
             const cond = try expr(&continue_scope, &continue_scope.base, bool_rl, while_full.ast.cond_expr);
@@ -5755,7 +5756,7 @@ fn whileExpr(
                 else
                     .err_union_payload_unsafe;
                 // will add this instruction to then_scope.instructions below
-                payload_inst = try then_scope.makeUnNode(tag, cond.inst, node);
+                payload_inst = try then_scope.makeUnNode(tag, cond.inst, while_full.ast.cond_expr);
                 const ident_token = if (payload_is_ref) payload_token + 1 else payload_token;
                 const ident_bytes = tree.tokenSlice(ident_token);
                 if (mem.eql(u8, "_", ident_bytes))
@@ -5784,7 +5785,7 @@ fn whileExpr(
             else
                 .optional_payload_unsafe;
             // will add this instruction to then_scope.instructions below
-            payload_inst = try then_scope.makeUnNode(tag, cond.inst, node);
+            payload_inst = try then_scope.makeUnNode(tag, cond.inst, while_full.ast.cond_expr);
             const ident_name = try astgen.identAsString(ident_token);
             const ident_bytes = tree.tokenSlice(ident_token);
             if (mem.eql(u8, "_", ident_bytes))
@@ -5860,7 +5861,7 @@ fn whileExpr(
                     .err_union_code_ptr
                 else
                     .err_union_code;
-                const else_payload_inst = try else_scope.addUnNode(tag, cond.inst, node);
+                const else_payload_inst = try else_scope.addUnNode(tag, cond.inst, while_full.ast.cond_expr);
                 const ident_name = try astgen.identAsString(error_token);
                 const ident_bytes = tree.tokenSlice(error_token);
                 if (mem.eql(u8, ident_bytes, "_"))
diff --git a/test/cases/compile_errors/packed_union_given_enum_tag_type.zig b/test/cases/compile_errors/packed_union_given_enum_tag_type.zig
new file mode 100644
index 0000000000000000000000000000000000000000..03aaef0d8cd560a461cc0673594eec990717c73d
--- /dev/null
+++ b/test/cases/compile_errors/packed_union_given_enum_tag_type.zig
@@ -0,0 +1,20 @@
+const Letter = enum {
+    A,
+    B,
+    C,
+};
+const Payload = packed union(Letter) {
+    A: i32,
+    B: f64,
+    C: bool,
+};
+export fn entry() void {
+    var a = Payload { .A = 1234 };
+    _ = a;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :6:30: error: packed union does not support enum tag type
diff --git a/test/cases/compile_errors/packed_union_with_automatic_layout_field.zig b/test/cases/compile_errors/packed_union_with_automatic_layout_field.zig
new file mode 100644
index 0000000000000000000000000000000000000000..97771e9b784347306f253ddf688a7f516e4afd0f
--- /dev/null
+++ b/test/cases/compile_errors/packed_union_with_automatic_layout_field.zig
@@ -0,0 +1,20 @@
+const Foo = struct {
+    a: u32,
+    b: f32,
+};
+const Payload = packed union {
+    A: Foo,
+    B: bool,
+};
+export fn entry() void {
+    var a = Payload { .B = true };
+    _ = a;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :6:5: error: packed unions cannot contain fields of type 'tmp.Foo'
+// :6:5: note: only packed structs layout are allowed in packed types
+// :1:13: note: struct declared here
diff --git a/test/cases/compile_errors/specify_non-integer_enum_tag_type.zig b/test/cases/compile_errors/specify_non-integer_enum_tag_type.zig
new file mode 100644
index 0000000000000000000000000000000000000000..f2ff3e2cd142254ec001de6e54bc88277b9c6e7c
--- /dev/null
+++ b/test/cases/compile_errors/specify_non-integer_enum_tag_type.zig
@@ -0,0 +1,16 @@
+const Small = enum (f32) {
+    One,
+    Two,
+    Three,
+};
+
+export fn entry() void {
+    var x = Small.One;
+    _ = x;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :1:21: error: expected integer tag type, found 'f32'
diff --git a/test/cases/compile_errors/stage1/obj/packed_union_given_enum_tag_type.zig b/test/cases/compile_errors/stage1/obj/packed_union_given_enum_tag_type.zig
deleted file mode 100644
index fceb7af65c7c643273d0b490ef1884042296505e..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/packed_union_given_enum_tag_type.zig
+++ /dev/null
@@ -1,20 +0,0 @@
-const Letter = enum {
-    A,
-    B,
-    C,
-};
-const Payload = packed union(Letter) {
-    A: i32,
-    B: f64,
-    C: bool,
-};
-export fn entry() void {
-    var a = Payload { .A = 1234 };
-    _ = a;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:6:30: error: packed union does not support enum tag type
diff --git a/test/cases/compile_errors/stage1/obj/packed_union_with_automatic_layout_field.zig b/test/cases/compile_errors/stage1/obj/packed_union_with_automatic_layout_field.zig
deleted file mode 100644
index 99ad6ca306aaeb666ef9b62cc4fb31c2f045486b..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/packed_union_with_automatic_layout_field.zig
+++ /dev/null
@@ -1,18 +0,0 @@
-const Foo = struct {
-    a: u32,
-    b: f32,
-};
-const Payload = packed union {
-    A: Foo,
-    B: bool,
-};
-export fn entry() void {
-    var a = Payload { .B = true };
-    _ = a;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:6:5: error: non-packed, non-extern struct 'Foo' not allowed in packed union; no guaranteed in-memory representation
diff --git a/test/cases/compile_errors/stage1/obj/specify_non-integer_enum_tag_type.zig b/test/cases/compile_errors/stage1/obj/specify_non-integer_enum_tag_type.zig
deleted file mode 100644
index 333647e1e392afb22f7596385ceace2d6a01a48c..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/specify_non-integer_enum_tag_type.zig
+++ /dev/null
@@ -1,16 +0,0 @@
-const Small = enum (f32) {
-    One,
-    Two,
-    Three,
-};
-
-export fn entry() void {
-    var x = Small.One;
-    _ = x;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:1:21: error: expected integer, found 'f32'
diff --git a/test/cases/compile_errors/stage1/obj/unused_variable_error_on_errdefer.zig b/test/cases/compile_errors/stage1/obj/unused_variable_error_on_errdefer.zig
deleted file mode 100644
index b85d5729dcf8f62c23cdee35a1a3fa873ff42768..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/unused_variable_error_on_errdefer.zig
+++ /dev/null
@@ -1,13 +0,0 @@
-fn foo() !void {
-    errdefer |a| unreachable;
-    return error.A;
-}
-export fn entry() void {
-    foo() catch unreachable;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:2:15: error: unused variable: 'a'
diff --git a/test/cases/compile_errors/stage1/obj/vector_index_out_of_bounds.zig b/test/cases/compile_errors/stage1/obj/vector_index_out_of_bounds.zig
deleted file mode 100644
index fdffd8b45567777d9dc61263f24a724d019a9431..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/vector_index_out_of_bounds.zig
+++ /dev/null
@@ -1,10 +0,0 @@
-export fn entry() void {
-    const x = @import("std").meta.Vector(3, f32){ 25, 75, 5, 0 };
-    _ = x;
-}
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:2:62: error: index 3 outside vector of size 3
diff --git a/test/cases/compile_errors/stage1/obj/while_expected_error_union_got_bool.zig b/test/cases/compile_errors/stage1/obj/while_expected_error_union_got_bool.zig
deleted file mode 100644
index b8a72e97937e454aa404e0c744fef8549d33d4ce..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/while_expected_error_union_got_bool.zig
+++ /dev/null
@@ -1,10 +0,0 @@
-export fn foo() void {
-    while (bar()) |x| {_ = x;} else |err| {_ = err;}
-}
-fn bar() bool { return true; }
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:2:15: error: expected error union type, found 'bool'
diff --git a/test/cases/compile_errors/stage1/obj/while_expected_error_union_got_optional.zig b/test/cases/compile_errors/stage1/obj/while_expected_error_union_got_optional.zig
deleted file mode 100644
index c933dc95092aa2bc4637f9dd9498cfe8771496a1..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/while_expected_error_union_got_optional.zig
+++ /dev/null
@@ -1,10 +0,0 @@
-export fn foo() void {
-    while (bar()) |x| {_ = x;} else |err| {_ = err;}
-}
-fn bar() ?i32 { return 1; }
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:2:15: error: expected error union type, found '?i32'
diff --git a/test/cases/compile_errors/stage1/obj/while_expected_optional_got_bool.zig b/test/cases/compile_errors/stage1/obj/while_expected_optional_got_bool.zig
deleted file mode 100644
index 0458d1ba0179951341bfbbf6e2d78df4ab315a02..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/while_expected_optional_got_bool.zig
+++ /dev/null
@@ -1,10 +0,0 @@
-export fn foo() void {
-    while (bar()) |x| {_ = x;}
-}
-fn bar() bool { return true; }
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:2:15: error: expected optional type, found 'bool'
diff --git a/test/cases/compile_errors/stage1/obj/while_expected_optional_got_error_union.zig b/test/cases/compile_errors/stage1/obj/while_expected_optional_got_error_union.zig
deleted file mode 100644
index 7cdbd2cccf69ad800659f21f13eabaa6177f6757..0000000000000000000000000000000000000000
--- a/test/cases/compile_errors/stage1/obj/while_expected_optional_got_error_union.zig
+++ /dev/null
@@ -1,10 +0,0 @@
-export fn foo() void {
-    while (bar()) |x| {_ = x;}
-}
-fn bar() anyerror!i32 { return 1; }
-
-// error
-// backend=stage1
-// target=native
-//
-// tmp.zig:2:15: error: expected optional type, found 'anyerror!i32'
diff --git a/test/cases/compile_errors/unused_variable_error_on_errdefer.zig b/test/cases/compile_errors/unused_variable_error_on_errdefer.zig
new file mode 100644
index 0000000000000000000000000000000000000000..4c37af04ebc58858d1cdc4d66b00d39362be1b0a
--- /dev/null
+++ b/test/cases/compile_errors/unused_variable_error_on_errdefer.zig
@@ -0,0 +1,13 @@
+fn foo() !void {
+    errdefer |a| unreachable;
+    return error.A;
+}
+export fn entry() void {
+    foo() catch unreachable;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:15: error: unused capture
diff --git a/test/cases/compile_errors/vector_index_out_of_bounds.zig b/test/cases/compile_errors/vector_index_out_of_bounds.zig
new file mode 100644
index 0000000000000000000000000000000000000000..ed1a25a32150006332f3b8c165b8ebd65b77f866
--- /dev/null
+++ b/test/cases/compile_errors/vector_index_out_of_bounds.zig
@@ -0,0 +1,10 @@
+export fn entry() void {
+    const x = @import("std").meta.Vector(3, f32){ 25, 75, 5, 0 };
+    _ = x;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:49: error: expected 3 vector elements; found 4
diff --git a/test/cases/compile_errors/while_expected_error_union_got_bool.zig b/test/cases/compile_errors/while_expected_error_union_got_bool.zig
new file mode 100644
index 0000000000000000000000000000000000000000..f7960437ec55619ecc0fd137fa99f5c6f109d08f
--- /dev/null
+++ b/test/cases/compile_errors/while_expected_error_union_got_bool.zig
@@ -0,0 +1,10 @@
+export fn foo() void {
+    while (bar()) |x| {_ = x;} else |err| {_ = err;}
+}
+fn bar() bool { return true; }
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:15: error: expected error union type, found 'bool'
diff --git a/test/cases/compile_errors/while_expected_error_union_got_optional.zig b/test/cases/compile_errors/while_expected_error_union_got_optional.zig
new file mode 100644
index 0000000000000000000000000000000000000000..5cabd76fce3fdca65a4f32eab0f45f8a0d91e9f4
--- /dev/null
+++ b/test/cases/compile_errors/while_expected_error_union_got_optional.zig
@@ -0,0 +1,10 @@
+export fn foo() void {
+    while (bar()) |x| {_ = x;} else |err| {_ = err;}
+}
+fn bar() ?i32 { return 1; }
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:15: error: expected error union type, found '?i32'
diff --git a/test/cases/compile_errors/while_expected_optional_got_bool.zig b/test/cases/compile_errors/while_expected_optional_got_bool.zig
new file mode 100644
index 0000000000000000000000000000000000000000..22b8c1e58c732c4ad7125772fa47562655e80adc
--- /dev/null
+++ b/test/cases/compile_errors/while_expected_optional_got_bool.zig
@@ -0,0 +1,10 @@
+export fn foo() void {
+    while (bar()) |x| {_ = x;}
+}
+fn bar() bool { return true; }
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:15: error: expected optional type, found 'bool'
diff --git a/test/cases/compile_errors/while_expected_optional_got_error_union.zig b/test/cases/compile_errors/while_expected_optional_got_error_union.zig
new file mode 100644
index 0000000000000000000000000000000000000000..38a8a0dd20387ea7b1ec00426ed1073b970db83c
--- /dev/null
+++ b/test/cases/compile_errors/while_expected_optional_got_error_union.zig
@@ -0,0 +1,10 @@
+export fn foo() void {
+    while (bar()) |x| {_ = x;}
+}
+fn bar() anyerror!i32 { return 1; }
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:15: error: expected optional type, found 'anyerror!i32'