--- a/spec/util_format_spec.lua	Tue Jun 29 16:07:57 2021 +0200
+++ b/spec/util_format_spec.lua	Tue Jun 29 16:18:31 2021 +0200
@@ -4,10 +4,10 @@
 	describe("#format()", function()
 		it("should work", function()
 			assert.equal("hello", format("%s", "hello"));
-			assert.equal("<nil>", format("%s"));
-			assert.equal("<nil>", format("%d"));
-			assert.equal("<nil>", format("%q"));
-			assert.equal(" [<nil>]", format("", nil));
+			assert.equal("(nil)", format("%s"));
+			assert.equal("(nil)", format("%d"));
+			assert.equal("(nil)", format("%q"));
+			assert.equal(" [(nil)]", format("", nil));
 			assert.equal("true", format("%s", true));
 			assert.equal("[true]", format("%d", true));
 			assert.equal("% [true]", format("%%", true));

--- a/util/format.lua	Tue Jun 29 16:07:57 2021 +0200
+++ b/util/format.lua	Tue Jun 29 16:18:31 2021 +0200
@@ -55,7 +55,7 @@
 			local option = spec:sub(-1);
 			if arg == nil then
 				args[i] = "nil";
-				spec = "<%s>";
+				spec = "(%s)";
 			elseif option == "q" then
 				args[i] = dump(arg);
 				spec = "%s";
@@ -77,7 +77,7 @@
 		i = i + 1;
 		local arg = args[i];
 		if arg == nil then
-			args[i] = "<nil>";
+			args[i] = "(nil)";
 		else
 			args[i] = tostring(arg);
 		end