diff --git a/build.zig b/build.zig
index 5896ab1a8c9dafd2e769588172a23bedc1642ac1..7849245462b2fddf1271091ee23afa0c7488ca04 100644
--- a/build.zig
+++ b/build.zig
@@ -613,7 +613,8 @@ fn addCxxKnownPath(
         ctx.cxx_compiler,
         b.fmt("-print-file-name={s}", .{objname}),
     });
-    const path_unpadded = mem.tokenize(u8, path_padded, "\r\n").next().?;
+    var tokenizer = mem.tokenize(u8, path_padded, "\r\n");
+    const path_unpadded = tokenizer.next().?;
     if (mem.eql(u8, path_unpadded, objname)) {
         if (errtxt) |msg| {
             std.debug.print("{s}", .{msg});
diff --git a/src/Sema.zig b/src/Sema.zig
index 3afc6e2bd3be9a5f4316053932d383a26c691ae0..aa276856581fa7010c460216617507fdc1afdb11 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -2317,8 +2317,8 @@ fn zirErrorSetDecl(
     const extra_index_end = extra_index + (extra.data.fields_len * 2);
     while (extra_index < extra_index_end) : (extra_index += 2) { // +2 to skip over doc_string
         const str_index = sema.code.extra[extra_index];
-        const name = try new_decl_arena_allocator.dupe(u8, sema.code.nullTerminatedString(str_index));
-        const result = names.getOrPutAssumeCapacity(name);
+        const kv = try sema.mod.getErrorValue(sema.code.nullTerminatedString(str_index));
+        const result = names.getOrPutAssumeCapacity(kv.key);
         assert(!result.found_existing); // verified in AstGen
     }
 
@@ -3661,8 +3661,12 @@ fn zirParamType(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!A
         fn_ty.fnInfo();
 
     if (param_index >= fn_info.param_types.len) {
-        assert(fn_info.is_var_args);
-        return sema.addType(Type.initTag(.var_args_param));
+        if (fn_info.is_var_args) {
+            return sema.addType(Type.initTag(.var_args_param));
+        }
+        // TODO implement begin_call/end_call Zir instructions and check
+        // argument count before casting arguments to parameter types.
+        return sema.fail(block, callee_src, "wrong number of arguments", .{});
     }
 
     if (fn_info.param_types[param_index].tag() == .generic_poison) {
@@ -13159,11 +13163,10 @@ fn zirReify(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.I
                 // TODO use reflection instead of magic numbers here
                 // error_set: type,
                 const name_val = struct_val[0];
+                const name_str = try name_val.toAllocatedBytes(Type.initTag(.const_slice_u8), sema.arena, target);
 
-                names.putAssumeCapacityNoClobber(
-                    try name_val.toAllocatedBytes(Type.initTag(.const_slice_u8), sema.arena, target),
-                    {},
-                );
+                const kv = try sema.mod.getErrorValue(name_str);
+                names.putAssumeCapacityNoClobber(kv.key, {});
             }
 
             // names must be sorted
diff --git a/src/value.zig b/src/value.zig
index 0467f0362ce452611a6f59c376ee5fb47afb3f5c..926a52c2b710dd8e48ae1a925ba2ee51b8d5f917 100644
--- a/src/value.zig
+++ b/src/value.zig
@@ -461,7 +461,7 @@ pub const Value = extern union {
             => unreachable,
 
             .ty, .lazy_align => {
-                const payload = self.castTag(.ty).?;
+                const payload = self.cast(Payload.Ty).?;
                 const new_payload = try arena.create(Payload.Ty);
                 new_payload.* = .{
                     .base = payload.base,
@@ -718,7 +718,7 @@ pub const Value = extern union {
             .lazy_align => {
                 try out_stream.writeAll("@alignOf(");
                 try val.castTag(.lazy_align).?.data.dump("", options, out_stream);
-                try out_stream.writeAll(")");
+                return try out_stream.writeAll(")");
             },
             .int_type => {
                 const int_type = val.castTag(.int_type).?.data;
@@ -2478,6 +2478,13 @@ pub const Value = extern union {
             .the_only_possible_value,
             => return hashInt(ptr_val, hasher, target),
 
+            .lazy_align => {
+                // Bit weird to have this here but this function is also called
+                // on integers.
+                const ty = ptr_val.castTag(.lazy_align).?.data;
+                ty.hashWithHasher(hasher, target);
+            },
+
             else => unreachable,
         }
     }