diff --git a/test/c_abi/main.zig b/test/c_abi/main.zig
index f8aac77eb5..d845f89eee 100644
--- a/test/c_abi/main.zig
+++ b/test/c_abi/main.zig
@@ -278,7 +278,7 @@ test "C ABI big struct" {
     if (comptime builtin.cpu.arch.isMIPS()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
 
-    var s = BigStruct{
+    const s = BigStruct{
         .a = 1,
         .b = 2,
         .c = 3,
@@ -304,7 +304,7 @@ extern fn c_big_union(BigUnion) void;
 test "C ABI big union" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
 
-    var x = BigUnion{
+    const x = BigUnion{
         .a = BigStruct{
             .a = 1,
             .b = 2,
@@ -339,13 +339,13 @@ test "C ABI medium struct of ints and floats" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var s = MedStructMixed{
+    const s = MedStructMixed{
         .a = 1234,
         .b = 100.0,
         .c = 1337.0,
     };
     c_med_struct_mixed(s);
-    var s2 = c_ret_med_struct_mixed();
+    const s2 = c_ret_med_struct_mixed();
     try expect(s2.a == 1234);
     try expect(s2.b == 100.0);
     try expect(s2.c == 1337.0);
@@ -372,14 +372,14 @@ test "C ABI small struct of ints" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var s = SmallStructInts{
+    const s = SmallStructInts{
         .a = 1,
         .b = 2,
         .c = 3,
         .d = 4,
     };
     c_small_struct_ints(s);
-    var s2 = c_ret_small_struct_ints();
+    const s2 = c_ret_small_struct_ints();
     try expect(s2.a == 1);
     try expect(s2.b == 2);
     try expect(s2.c == 3);
@@ -407,13 +407,13 @@ test "C ABI medium struct of ints" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var s = MedStructInts{
+    const s = MedStructInts{
         .x = 1,
         .y = 2,
         .z = 3,
     };
     c_med_struct_ints(s);
-    var s2 = c_ret_med_struct_ints();
+    const s2 = c_ret_med_struct_ints();
     try expect(s2.x == 1);
     try expect(s2.y == 2);
     try expect(s2.z == 3);
@@ -442,9 +442,9 @@ export fn zig_small_packed_struct(x: SmallPackedStruct) void {
 }
 
 test "C ABI small packed struct" {
-    var s = SmallPackedStruct{ .a = 0, .b = 1, .c = 2, .d = 3 };
+    const s = SmallPackedStruct{ .a = 0, .b = 1, .c = 2, .d = 3 };
     c_small_packed_struct(s);
-    var s2 = c_ret_small_packed_struct();
+    const s2 = c_ret_small_packed_struct();
     try expect(s2.a == 0);
     try expect(s2.b == 1);
     try expect(s2.c == 2);
@@ -466,9 +466,9 @@ export fn zig_big_packed_struct(x: BigPackedStruct) void {
 test "C ABI big packed struct" {
     if (!has_i128) return error.SkipZigTest;
 
-    var s = BigPackedStruct{ .a = 1, .b = 2 };
+    const s = BigPackedStruct{ .a = 1, .b = 2 };
     c_big_packed_struct(s);
-    var s2 = c_ret_big_packed_struct();
+    const s2 = c_ret_big_packed_struct();
     try expect(s2.a == 1);
     try expect(s2.b == 2);
 }
@@ -486,7 +486,7 @@ test "C ABI split struct of ints" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var s = SplitStructInt{
+    const s = SplitStructInt{
         .a = 1234,
         .b = 100,
         .c = 1337,
@@ -514,13 +514,13 @@ test "C ABI split struct of ints and floats" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var s = SplitStructMixed{
+    const s = SplitStructMixed{
         .a = 1234,
         .b = 100,
         .c = 1337.0,
     };
     c_split_struct_mixed(s);
-    var s2 = c_ret_split_struct_mixed();
+    const s2 = c_ret_split_struct_mixed();
     try expect(s2.a == 1234);
     try expect(s2.b == 100);
     try expect(s2.c == 1337.0);
@@ -541,14 +541,14 @@ test "C ABI sret and byval together" {
     if (comptime builtin.cpu.arch.isMIPS()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
 
-    var s = BigStruct{
+    const s = BigStruct{
         .a = 1,
         .b = 2,
         .c = 3,
         .d = 4,
         .e = 5,
     };
-    var y = c_big_struct_both(s);
+    const y = c_big_struct_both(s);
     try expect(y.a == 10);
     try expect(y.b == 11);
     try expect(y.c == 12);
@@ -562,7 +562,7 @@ export fn zig_big_struct_both(x: BigStruct) BigStruct {
     expect(x.c == 32) catch @panic("test failure");
     expect(x.d == 33) catch @panic("test failure");
     expect(x.e == 34) catch @panic("test failure");
-    var s = BigStruct{
+    const s = BigStruct{
         .a = 20,
         .b = 21,
         .c = 22,
@@ -594,7 +594,7 @@ test "C ABI structs of floats as parameter" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var v3 = Vector3{
+    const v3 = Vector3{
         .x = 3.0,
         .y = 6.0,
         .z = 12.0,
@@ -602,7 +602,7 @@ test "C ABI structs of floats as parameter" {
     c_small_struct_floats(v3);
     c_small_struct_floats_extra(v3, "hello");
 
-    var v5 = Vector5{
+    const v5 = Vector5{
         .x = 76.0,
         .y = -1.0,
         .z = -12.0,
@@ -634,13 +634,13 @@ test "C ABI structs of ints as multiple parameters" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC64()) return error.SkipZigTest;
 
-    var r1 = Rect{
+    const r1 = Rect{
         .left = 1,
         .right = 21,
         .top = 16,
         .bottom = 4,
     };
-    var r2 = Rect{
+    const r2 = Rect{
         .left = 178,
         .right = 189,
         .top = 21,
@@ -671,13 +671,13 @@ test "C ABI structs of floats as multiple parameters" {
     if (comptime builtin.cpu.arch.isMIPS()) return error.SkipZigTest;
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
 
-    var r1 = FloatRect{
+    const r1 = FloatRect{
         .left = 1,
         .right = 21,
         .top = 16,
         .bottom = 4,
     };
-    var r2 = FloatRect{
+    const r2 = FloatRect{
         .left = 178,
         .right = 189,
         .top = 21,
@@ -787,7 +787,7 @@ test "Struct with array as padding." {
 
     c_struct_with_array(.{ .a = 1, .padding = undefined, .b = 2 });
 
-    var x = c_ret_struct_with_array();
+    const x = c_ret_struct_with_array();
     try expect(x.a == 4);
     try expect(x.b == 155);
 }
@@ -822,7 +822,7 @@ test "Float array like struct" {
         },
     });
 
-    var x = c_ret_float_array_struct();
+    const x = c_ret_float_array_struct();
     try expect(x.origin.x == 1);
     try expect(x.origin.y == 2);
     try expect(x.size.width == 3);
@@ -840,7 +840,7 @@ test "small simd vector" {
 
     c_small_vec(.{ 1, 2 });
 
-    var x = c_ret_small_vec();
+    const x = c_ret_small_vec();
     try expect(x[0] == 3);
     try expect(x[1] == 4);
 }
@@ -858,7 +858,7 @@ test "medium simd vector" {
 
     c_medium_vec(.{ 1, 2, 3, 4 });
 
-    var x = c_ret_medium_vec();
+    const x = c_ret_medium_vec();
     try expect(x[0] == 5);
     try expect(x[1] == 6);
     try expect(x[2] == 7);
@@ -879,7 +879,7 @@ test "big simd vector" {
 
     c_big_vec(.{ 1, 2, 3, 4, 5, 6, 7, 8 });
 
-    var x = c_ret_big_vec();
+    const x = c_ret_big_vec();
     try expect(x[0] == 9);
     try expect(x[1] == 10);
     try expect(x[2] == 11);
@@ -903,7 +903,7 @@ test "C ABI pointer sized float struct" {
 
     c_ptr_size_float_struct(.{ .x = 1, .y = 2 });
 
-    var x = c_ret_ptr_size_float_struct();
+    const x = c_ret_ptr_size_float_struct();
     try expect(x.x == 3);
     try expect(x.y == 4);
 }
@@ -1102,6 +1102,7 @@ test "C function that takes byval struct called via function pointer" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
 
     var fn_ptr = &c_func_ptr_byval;
+    _ = &fn_ptr;
     fn_ptr(
         @as(*anyopaque, @ptrFromInt(1)),
         @as(*anyopaque, @ptrFromInt(2)),
@@ -1224,7 +1225,7 @@ extern fn stdcall_big_union(BigUnion) callconv(stdcall_callconv) void;
 test "Stdcall ABI big union" {
     if (comptime builtin.cpu.arch.isPPC()) return error.SkipZigTest;
 
-    var x = BigUnion{
+    const x = BigUnion{
         .a = BigStruct{
             .a = 1,
             .b = 2,
diff --git a/test/compare_output.zig b/test/compare_output.zig
index bcdc642a1e..d30b6714c9 100644
--- a/test/compare_output.zig
+++ b/test/compare_output.zig
@@ -165,7 +165,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\const y : u16 = 5678;
         \\pub fn main() void {
         \\    var x_local : i32 = print_ok(x);
-        \\    _ = x_local;
+        \\    _ = &x_local;
         \\}
         \\fn print_ok(val: @TypeOf(x)) @TypeOf(foo) {
         \\    _ = val;
@@ -504,7 +504,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\
         \\pub fn main() !void {
         \\    var allocator_buf: [10]u8 = undefined;
-        \\    var fba = std.heap.FixedBufferAllocator.init(&allocator_buf);
+        \\    const fba = std.heap.FixedBufferAllocator.init(&allocator_buf);
         \\    var fba_wrapped = std.mem.validationWrap(fba);
         \\    var logging_allocator = std.heap.loggingAllocator(fba_wrapped.allocator());
         \\    const allocator = logging_allocator.allocator();
diff --git a/test/link/wasm/archive/main.zig b/test/link/wasm/archive/main.zig
index 29be3af0ac..465f85f9f6 100644
--- a/test/link/wasm/archive/main.zig
+++ b/test/link/wasm/archive/main.zig
@@ -1,6 +1,7 @@
 export fn foo() void {
     var a: f16 = 2.2;
+    _ = &a;
     // this will pull-in compiler-rt
-    var b = @trunc(a);
+    const b = @trunc(a);
     _ = b;
 }
diff --git a/test/src/Cases.zig b/test/src/Cases.zig
index c8265a4165..f533af37d7 100644
--- a/test/src/Cases.zig
+++ b/test/src/Cases.zig
@@ -1161,10 +1161,7 @@ const TestManifest = struct {
     fn getDefaultParser(comptime T: type) ParseFn(T) {
         if (T == CrossTarget) return struct {
             fn parse(str: []const u8) anyerror!T {
-                var opts = CrossTarget.ParseOptions{
-                    .arch_os_abi = str,
-                };
-                return try CrossTarget.parse(opts);
+                return CrossTarget.parse(.{ .arch_os_abi = str });
             }
         }.parse;
 
@@ -1691,7 +1688,7 @@ fn runOneCase(
                 var argv = std.ArrayList([]const u8).init(allocator);
                 defer argv.deinit();
 
-                var exec_result = x: {
+                const exec_result = x: {
                     var exec_node = update_node.start("execute", 0);
                     exec_node.activate();
                     defer exec_node.end();
diff --git a/test/standalone/extern/main.zig b/test/standalone/extern/main.zig
index 4cbed184c3..3f5168f841 100644
--- a/test/standalone/extern/main.zig
+++ b/test/standalone/extern/main.zig
@@ -6,8 +6,8 @@ const getHidden = @extern(*const fn () callconv(.C) u32, .{ .name = "getHidden"
 const T = extern struct { x: u32 };
 
 test {
-    var mut_val_ptr = @extern(*f64, .{ .name = "mut_val" });
-    var const_val_ptr = @extern(*const T, .{ .name = "const_val" });
+    const mut_val_ptr = @extern(*f64, .{ .name = "mut_val" });
+    const const_val_ptr = @extern(*const T, .{ .name = "const_val" });
 
     assert(getHidden() == 0);
     updateHidden(123);
diff --git a/test/standalone/main_return_error/error_u8_non_zero.zig b/test/standalone/main_return_error/error_u8_non_zero.zig
index c45458fb21..47fe7946ec 100644
--- a/test/standalone/main_return_error/error_u8_non_zero.zig
+++ b/test/standalone/main_return_error/error_u8_non_zero.zig
@@ -1,8 +1,7 @@
 const Err = error{Foo};
 
 fn foo() u8 {
-    var x = @as(u8, @intCast(9));
-    return x;
+    return @intCast(9);
 }
 
 pub fn main() !u8 {
diff --git a/test/standalone/stack_iterator/shared_lib_unwind.zig b/test/standalone/stack_iterator/shared_lib_unwind.zig
index 50e0421e2a..57513a49c6 100644
--- a/test/standalone/stack_iterator/shared_lib_unwind.zig
+++ b/test/standalone/stack_iterator/shared_lib_unwind.zig
@@ -9,7 +9,7 @@ noinline fn frame4(expected: *[5]usize, unwound: *[5]usize) void {
     var context: debug.ThreadContext = undefined;
     testing.expect(debug.getContext(&context)) catch @panic("failed to getContext");
 
-    var debug_info = debug.getSelfDebugInfo() catch @panic("failed to openSelfDebugInfo");
+    const debug_info = debug.getSelfDebugInfo() catch @panic("failed to openSelfDebugInfo");
     var it = debug.StackIterator.initWithContext(expected[0], debug_info, &context) catch @panic("failed to initWithContext");
     defer it.deinit();
 
diff --git a/test/standalone/stack_iterator/unwind.zig b/test/standalone/stack_iterator/unwind.zig
index 1280118173..4bb459bdac 100644
--- a/test/standalone/stack_iterator/unwind.zig
+++ b/test/standalone/stack_iterator/unwind.zig
@@ -9,7 +9,7 @@ noinline fn frame3(expected: *[4]usize, unwound: *[4]usize) void {
     var context: debug.ThreadContext = undefined;
     testing.expect(debug.getContext(&context)) catch @panic("failed to getContext");
 
-    var debug_info = debug.getSelfDebugInfo() catch @panic("failed to openSelfDebugInfo");
+    const debug_info = debug.getSelfDebugInfo() catch @panic("failed to openSelfDebugInfo");
     var it = debug.StackIterator.initWithContext(expected[0], debug_info, &context) catch @panic("failed to initWithContext");
     defer it.deinit();
 
@@ -76,7 +76,7 @@ noinline fn frame1(expected: *[4]usize, unwound: *[4]usize) void {
     // Use a stack frame that is too big to encode in __unwind_info's stack-immediate encoding
     // to exercise the stack-indirect encoding path
     var pad: [std.math.maxInt(u8) * @sizeOf(usize) + 1]u8 = undefined;
-    _ = pad;
+    _ = std.mem.doNotOptimizeAway(&pad);
 
     frame2(expected, unwound);
 }
diff --git a/test/standalone/use_alias/main.zig b/test/standalone/use_alias/main.zig
index be9d6da6c3..68ef6f6588 100644
--- a/test/standalone/use_alias/main.zig
+++ b/test/standalone/use_alias/main.zig
@@ -6,5 +6,6 @@ test "symbol exists" {
         .a = 1,
         .b = 1,
     };
+    _ = &foo;
     try expect(foo.a + foo.b == 2);
 }
diff --git a/test/standalone/windows_spawn/main.zig b/test/standalone/windows_spawn/main.zig
index a57b44c757..82e1b5b171 100644
--- a/test/standalone/windows_spawn/main.zig
+++ b/test/standalone/windows_spawn/main.zig
@@ -158,7 +158,7 @@ fn testExec(allocator: std.mem.Allocator, command: []const u8, expected_stdout:
 }
 
 fn testExecWithCwd(allocator: std.mem.Allocator, command: []const u8, cwd: ?[]const u8, expected_stdout: []const u8) !void {
-    var result = try std.ChildProcess.run(.{
+    const result = try std.ChildProcess.run(.{
         .allocator = allocator,
         .argv = &[_][]const u8{command},
         .cwd = cwd,
diff --git a/test/standalone/zerolength_check/src/main.zig b/test/standalone/zerolength_check/src/main.zig
index e1e2c5d376..1cb8358c9d 100644
--- a/test/standalone/zerolength_check/src/main.zig
+++ b/test/standalone/zerolength_check/src/main.zig
@@ -1,14 +1,14 @@
 const std = @import("std");
 
 test {
-    var dest = foo();
-    var source = foo();
+    const dest = foo();
+    const source = foo();
 
     @memcpy(dest, source);
     @memset(dest, 4);
     @memset(dest, undefined);
 
-    var dest2 = foo2();
+    const dest2 = foo2();
     @memset(dest2, 0);
 }