make args live through lifetime of runner

we just assign cloned runners the args of the parent runner and don't
free the parent's, maintaining okay memory usage.

src/runner.zig

@@ -26,10 +26,13 @@ pub const Runner = struct {
     /// If the runner is in REPL mode
     repl: bool = false,
 
+    args: [][]u8,
+
     pub fn init(allocator: *std.mem.Allocator, repl: bool) Runner {
         return Runner{
             .allocator = allocator,
             .repl = repl,
+            .args = std.process.argsAlloc(allocator) catch unreachable,
         };
     }
 
@@ -41,7 +44,11 @@ pub const Runner = struct {
 
     pub fn clone(self: *Runner) !Runner {
         var cloned_image = if (self.image) |image| try image.clone() else null;
-        return Runner{ .allocator = self.allocator, .image = cloned_image };
+        return Runner{
+            .allocator = self.allocator,
+            .image = cloned_image,
+            .args = self.args,
+        };
     }
 
     fn resolveArg(self: *Runner, load_path: []const u8) ![]const u8 {
@@ -57,14 +64,12 @@ pub const Runner = struct {
             // ':0' should ALWAYS point to the image.
             if (self.repl) index += 3 else index += 2;
 
-            var args = try std.process.argsAlloc(self.allocator);
-            defer std.process.argsFree(self.allocator, args);
-            std.debug.warn("ARGS!! {} \n", .{args.len});
-            for (args) |arg, idx| {
+            std.debug.warn("ARGS!! {} \n", .{self.args.len});
+            for (self.args) |arg, idx| {
                 std.debug.warn("arg{} = {}\n", .{ idx, arg });
             }
-            std.debug.warn("fetch arg idx={}, val={}\n", .{ index, args[index] });
-            return args[index];
+            std.debug.warn("fetch arg idx={}, val={}\n", .{ index, self.args[index] });
+            return self.args[index];
         } else {
             return load_path;
         }